Google Ads Scripts: Automate the Checks You Forget

Smart Bidding is Google's umbrella term for automated bid strategies — Target CPA, Target ROAS, Maximise Conversions, Maximise Conversion Value — that use machine learning to set bids at auction time. The promise is compelling: the algorithm reads hundreds of contextual signals (device, location, time, audience, search query) and adjusts your bid in real time better than any human could manually. For large-budget advertisers with rich conversion histories, that promise largely holds up. For a $2k/month trade or clinic account in suburban Brisbane or Parramatta, it routinely doesn't — and the reason is data starvation, not a broken algorithm.

The 30–50 conversion threshold Google actually documents

Per Google Ads Help — About Smart Bidding, Target CPA and Target ROAS require a minimum of 30–50 conversions per campaign per month to exit the learning phase reliably and bid with statistical confidence. Below that threshold, the algorithm doesn't have enough signal to distinguish a high-intent auction from a low-intent one. Most $1k–$3k/month Australian service campaigns — a plumber in Melbourne's outer east, a physio clinic in Newcastle, a bookkeeper serving SMEs in Adelaide — generate fewer than 15 tracked conversions per month. Not because the jobs aren't happening, but because call conversions, form fills, and booked appointments are either untracked or misconfigured in Google Tag Manager.

What thin signals do to your auction price

When conversion signals are sparse, Google's auction doesn't shrug and carry on at your existing CPC. It treats your campaign as high-risk inventory. The algorithm can't confidently predict which impressions will convert, so it bids conservatively on the auctions it thinks are worth entering — and those tend to be the safer, more competitive, more expensive ones. The perverse result: your CPCs rise while your lead volume falls. You pay more per click and get fewer conversions per dollar. The SEMrush State of Search 2024 report noted that small-budget advertisers spending under $5,000 per month disproportionately reported CPC increases after switching to Target ROAS without sufficient conversion history. That's not coincidence — it's the direct consequence of under-signalled Smart Bidding.

The learning phase resets — often permanently for small accounts

According to Google Ads Help — Learning period for automated bid strategies, the learning phase typically lasts one to two weeks after a campaign is launched or a significant change is made. Significant changes include: editing your bid strategy target, changing your daily budget by more than 20%, pausing and resuming the campaign, adding new ad groups, and — critically — changing your conversion actions. For a small-budget account where the owner is actively iterating, that means the campaign may never exit learning. Every tweak restarts the clock. The algorithm spends its entire life in the cautious, expensive, under-performing state it was designed to outgrow.

Switching to Target CPA doesn't fix a conversion tracking problem — it accelerates it.

This is the part most YouTube tutorials and agency sales decks skip. The question of whether Smart Bidding is appropriate for your campaign isn't a preference question — it's an arithmetic question. And for most small Australian service businesses, the arithmetic doesn't work.

Running the numbers on a typical small-business account

Take a common scenario: a $2,000/month Google Ads budget, a Target CPA set at $150 (reasonable for a mid-tier trade or professional service), and a campaign running Search only. Divide budget by target CPA: $2,000 ÷ $150 = 13.3 conversions per month. That's the ceiling. Even if the campaign ran at perfect efficiency with zero wasted spend, it could mathematically generate only 13 conversions — well below the 30-conversion minimum Google's own documentation requires for stable automated bidding.

If your $2k/month campaign can only produce 13 conversions, Smart Bidding is mathematically set up to fail you.

Why the settings panel can't solve this

The instinct when a campaign underperforms is to open the settings and adjust something. Lower the target. Raise the budget. Tighten the keywords. Those are all reasonable levers — but none of them solve a structural conversion-volume problem. The only real fixes are: increase total budget so more conversions are possible, broaden match types to capture more qualifying traffic, or redesign your conversion architecture to count more meaningful micro-conversions (quote requests, phone clicks tied to actual call duration, appointment bookings) so the algorithm has more signal to learn from. Until the volume problem is solved, automated bidding is optimising toward a ceiling that's already set too low.

Raising your Target CPA isn't the answer either

A common (and understandable) response is: "I'll just raise my Target CPA so the algorithm spends the budget and generates more conversions." The problem is that raising your Target CPA doesn't create more qualified demand — it just tells the algorithm you're willing to pay more per lead. You'll get more conversions, but at a higher cost per acquisition, and you still won't hit the 30-conversion minimum unless your budget also increases proportionally. You've solved neither the volume problem nor the cost problem.

Even if your budget could theoretically support Smart Bidding, the conversion data feeding the algorithm may be fundamentally unreliable. When SoudCoh audits Google Ads accounts for Australian service businesses, conversion tracking misconfiguration is present in the majority of accounts — not occasionally, consistently. The issues follow predictable patterns.

Duplicate conversion actions: the most common silent killer

The most frequent problem SoudCoh finds is duplicate conversion actions: a Google Ads auto-imported conversion from Google Analytics 4 firing on a thank-you page URL, AND a manually created GTM tag also firing on the same thank-you page for the same event. Both actions are set to "Primary action — Bidding." Google counts both. The result looks like your campaign is performing well — the conversion count doubles — but the signal quality halves because the algorithm is now making decisions based on a noisy, redundant data set. It's the tracking equivalent of counting every sale twice on your Xero P&L.

To check for this in Google Ads:

1. Go to Tools → Conversions (or Measurement → Conversions in the new UI).
2. Filter the list by Category: Primary action.
3. Look at the Source column — if you see both a "Website" conversion and an "Imported from Google Analytics" conversion that correspond to the same user action (e.g., both named "Contact Form" or "Thank You Page"), one of them needs to be deleted or set to "Secondary — Observation."

Phone call conversions and low-intent inflation

Phone number click-throughs tracked as conversions are the second landmine. A click on a phone number in a mobile ad is not a booked job. It's not even a conversation. It's a tap that may have been accidental, or may have connected to voicemail, or may have been a supplier calling back. When these clicks are set as Primary bidding actions, they inflate your conversion count with low-intent signals and teach the algorithm that a phone-number tap is equivalent to a completed enquiry. Your reported CPA looks lower than reality; your actual cost-per-booked-job is much higher; and the algorithm keeps bidding on auctions that generate taps rather than jobs.

The fix is to either: (a) use Google's call duration filter — only count calls lasting more than 60 seconds as conversions — or (b) demote phone click conversions to "Secondary — Observation" and rely on form completions or appointment bookings as your primary bidding signal.

The 20-minute GTM check you can do tonight

1. Open Google Tag Manager → Preview and enter your website URL.
2. Navigate to your contact or enquiry page and submit a real test lead using a test email address.
3. In the GTM debug panel, click the confirmation/thank-you page event in the left-hand timeline.
4. Click Tags Fired on the right panel.
5. You should see exactly one Google Ads conversion tag firing. If you see two or more, you have duplicates. If you see zero, your tracking is broken entirely.

This one is specific to Australian businesses and almost never comes up in generic Google Ads content. If you're running a Target ROAS campaign and passing revenue values to Google as conversion values, the way you record that revenue matters — not just for your tax obligations, but for the accuracy of the machine learning model deciding where to spend your budget.

The 10% distortion hiding in your conversion values

Target ROAS works by dividing the total conversion value Google tracks by the total ad spend, then trying to hit a target ratio. If your conversion values include GST, your reported ROAS is inflated by 10% relative to the actual revenue your business retains. A campaign targeting 500% ROAS on GST-inclusive revenue is actually targeting 450% ROAS on real business income — and the algorithm is optimising toward the wrong number in every single auction.

The ATO's record-keeping guidance for business expenses requires you to keep records separating GST from business income. The same principle applies to your ad platform data: the value you pass to Google should reflect what the job is actually worth to your business after the ATO takes its 10%.

A concrete example: the plumber and the $1,100 job

A plumber in Western Sydney books a hot water system replacement for $1,100 (GST-inclusive). The actual revenue to the business is $1,000. If the conversion value passed to Google is $1,100, the algorithm learns that this type of job is worth $1,100 in bidding decisions. Over hundreds of auctions, that 10% error compounds. The algorithm overbids on job types it thinks are worth more than they are, exhausts budget faster, and when actual margins are reviewed at end-of-month, the real ROAS is consistently lower than the reported number. The business owner thinks the campaign is performing; the P&L says otherwise.

How to fix your conversion values tonight

1. In Google Ads, go to Tools → Conversions and open the relevant conversion action.
2. Under Value, check whether you're using a fixed value or a dynamic value passed from the website.
3. If using a fixed value, confirm the number entered is GST-exclusive (divide any GST-inclusive figure by 1.1).
4. If using a dynamic value passed via GTM or your e-commerce platform (common in Shopify or WooCommerce setups), check that the revenue variable in your data layer is pulling the ex-GST figure from your order system — not the total including tax.
5. If you're unsure what value to use, a conservative placeholder equal to your average job margin (not revenue) is more honest to the algorithm than a GST-inclusive revenue figure.

The Google Ads interface nudges you toward Smart Bidding at every opportunity. When you create a campaign, Target CPA or Maximise Conversions is the default. When you haven't enabled automated bidding, the interface shows a recommendation to switch. Most owner-operators either take the bait immediately — and end up in the learning-limbo situation this article describes — or reject automation entirely and run Manual CPC indefinitely, leaving real optimisation value on the table. There's a middle path that most skip: Enhanced CPC.

What Enhanced CPC actually does

Enhanced CPC (eCPC) sits between Manual CPC and full Smart Bidding on the automation spectrum. You set your manual bids, and Google applies automated adjustments of up to 30% upward (and downward, without limit) based on available conversion signals. It doesn't require the 30-conversion minimum that Target CPA demands. It works with thin conversion histories. And critically, it lets you accumulate clean, trustworthy conversion data over time — so that when you do eventually graduate to Target CPA, the algorithm already has a meaningful foundation to build on rather than starting blind.

The transition path that actually works

The correct progression for a sub-$5M Australian service business with a $1k–$3k/month Google Ads budget is not "Manual CPC → Target CPA." It's a three-stage path:

1. Manual CPC — use this while you fix your conversion tracking. Get your GTM audit done. Eliminate duplicates. Set GST-exclusive values. Do not change bid strategy while debugging tracking.
2. Enhanced CPC — once tracking is clean, switch to eCPC and run for a minimum of 60 days. Target accumulating 25 or more clean, primary conversions per month. Let the algorithm learn with guardrails.
3. Target CPA — only after you have 30+ clean conversions per month in your history and a reliable average CPA to reference. Set your initial Target CPA at 20% above your current actual CPA, not your desired CPA. Let the algorithm prove itself before tightening the target.

Why skipping straight to Target CPA is where small accounts go wrong

eCPC is not a lesser product. It's the appropriate tool for the conversion volume you currently have. Skipping it to go directly to Target CPA — because it sounds more sophisticated, or because a Google rep recommended it, or because a competitor mentioned it — is the single most common reason SoudCoh finds campaigns in perpetual learning mode when conducting audits on new client accounts. The algorithm needs history. eCPC is how you build it without surrendering bid control while you do.

You don't need an agency to do an initial pass on your conversion tracking. You need 20 minutes, access to Google Tag Manager and Google Ads, and the following checklist. Do this before you change a single bid strategy setting.

Step 1: GTM Preview — confirm exactly one tag fires per conversion

1. Log into Google Tag Manager and click Preview in the top right.
2. Enter your website URL and click Connect. Your site opens in a new tab with the GTM debug bar active.
3. Navigate to your contact, quote, or booking form and complete a test submission (use a test email like test@yourdomain.com.au so you can identify it later).
4. Return to the GTM debug panel. Click the thank-you page or confirmation page event in the left-hand timeline.
5. Under Tags Fired: you should see exactly one Google Ads Conversion Tracking tag. If you see two or more, identify which is the duplicate and pause it. If you see zero, your conversion tag is broken — check the trigger conditions.

Step 2: Google Ads Conversions — identify and remove duplicates

1. In Google Ads, navigate to Tools → Measurement → Conversions.
2. Add the Source column if it's not visible (click the columns icon).
3. Filter by Optimization: Primary action — Bidding.
4. Scan for any two conversion actions that represent the same real-world event — same form, same page — where one source is "Website" and another is "Imported from Google Analytics 4."
5. For the duplicate, click the action name → Settings → scroll to Conversion action optimization → change from "Primary action — Bidding" to "Secondary action — Observation."
6. Do not delete the duplicate yet — set it to Secondary first and monitor for 14 days to confirm the primary action is still recording correctly.

Step 3: Verify your conversion values are GST-exclusive

1. Still in Tools → Conversions, open each conversion action set to Primary.
2. Under Value, note the figure. If it's a round number like $1,100, $550, or $220, it's almost certainly GST-inclusive — divide by 1.1 and update.
3. If value is dynamic (pulled from your website), check your GTM container for the conversion value variable. Open the tag → locate the Conversion Value field → confirm it references a data layer variable that passes ex-GST revenue.
4. If you run Xero or MYOB and your booking software (e.g., ServiceM8, Cliniko, Timely) passes total invoice values, check whether that integration sends tax-inclusive or tax-exclusive amounts before trusting the number.

Before you open your Google Ads settings, answer one question: how many clean, non-duplicate, primary-action conversions did your campaign record last month? Not the number in the dashboard — the number after you've completed the audit above and removed duplicates and phone-click inflation. That single number determines everything else.

Under 15 conversions per month

Smart Bidding is not appropriate for your campaign right now, regardless of what your agency, a Google representative, or a YouTube tutorial told you. Use Manual CPC. Complete the GTM audit above. Fix duplicate tracking. Set correct GST-exclusive conversion values. Do not touch the bid strategy until you've resolved the data integrity issues — because every week you run Smart Bidding on bad data, you're training the algorithm in the wrong direction, and that history doesn't erase itself quickly.

15–29 conversions per month

You're in the transition zone. Enhanced CPC is your home for the next 60 days. Run eCPC, keep monitoring for duplicate conversions, and focus on growing volume — broader match types, additional ad groups, testing different landing pages to improve conversion rate. Your goal is to reach 30 clean conversions per month before considering Target CPA.

30 or more clean conversions per month

Target CPA is worth testing — but configure it correctly. Set your initial Target CPA at your current actual CPA plus 20%. Not your desired CPA. Not a number that looks good in a report. Your actual average cost per conversion from the past 30 days, multiplied by 1.2. This gives the algorithm room to operate without immediately restricting spend below what's needed to generate volume.

One critical sequencing rule

Make all tracking fixes before you change the bid strategy. Not simultaneously. Before. Every bid strategy change resets the learning phase. If you fix your GTM and switch to Target CPA on the same day, you've started the learning clock with freshly corrected data — which sounds fine, but means you won't have a clean historical baseline to compare against. Fix tracking first, run for two weeks under the existing strategy, confirm the conversion numbers look right, then change the bid strategy. This order matters.

Most agencies start a Google Ads engagement by touching the campaigns — adjusting bids, restructuring ad groups, rewriting ad copy. SoudCoh's Google Ads service starts differently: the first 30 days are a data-integrity phase, not an optimisation phase. Here's why, and what it looks like in practice.

The conversion audit: what it covers and what it produces

Before a single bid strategy recommendation is made, SoudCoh runs a structured conversion audit across three platforms: Google Tag Manager, Google Ads, and Google Analytics 4. The audit identifies:

• Duplicate conversion actions set to Primary bidding
• Misconfigured GTM triggers firing on the wrong page or event
• GST-inclusive conversion values being passed to Google
• Phone click conversions incorrectly set as Primary bidding signals
• GA4 import conflicts with native Google Ads conversion tags
• Conversion actions for defunct pages or forms that no longer exist

The audit produces two deliverables: a GTM container screenshot showing exactly which tags are active and what triggers them, and a conversion action report from Google Ads showing which actions are set to Primary versus Secondary — so the business owner can see, in plain terms, what the algorithm is and isn't using to make bidding decisions. No jargon. No dashboard screenshot without explanation.

Why optimising on bad data accelerates the wrong direction

When an account has duplicate conversions or GST-inclusive values, every optimisation decision made on top of that data makes things worse, not better. Lowering a Target CPA when the reported CPA is inflated by duplicates means you're tightening the algorithm toward a target that was never real. Raising a ROAS target when conversion values include GST means you're pushing the algorithm to find jobs that return 550% when the real return was 500% all along. Optimisation amplifies whatever signal you give it. If the signal is distorted, optimisation amplifies the distortion.

What the engagement looks like after the audit

Once the data-integrity phase is complete and tracking is verified clean — confirmed by two weeks of stable, deduplicated conversion recording — SoudCoh then makes bid strategy recommendations based on actual conversion volume. If the account has fewer than 30 conversions per month, the recommendation is Enhanced CPC with a documented path to Target CPA. If volume supports Target CPA, the initial target is set at actual CPA plus 20%, not a client's wishlist number. If Target ROAS is appropriate, conversion values are verified ex-GST before the strategy is activated.

You can see the full engagement structure — including the data-integrity phase, the reporting cadence, and what's included in month one versus ongoing — on the SoudCoh Google Ads services page. If you want to see how this has played out for Australian service businesses in practice, the case studies section covers specific account scenarios including a trade services client in Victoria and a health clinic in Queensland.

What to do next: Before you adjust a single setting in your Google Ads account, run the 20-minute GTM audit in section six of this article and count your clean monthly conversions. If the number is under 30, you now know why Smart Bidding is underdelivering — and the fix is in your tracking, not your targets. Book a free Google Ads conversion audit through the way we run a Google Ads account and find out in 30 minutes whether your tracking is ready for Smart Bidding — or whether you're paying more for less because the algorithm is flying blind.