Google Ads7 min read

Smart Bidding Without Enough Conversion Data: A Playbook for the First 90 Days

A

Ashton

Founder, Buttercup Digital Solutions - 8 June 2026

Google's official guidance is around 30 conversions per campaign in the last 30 days before Smart Bidding strategies stabilise. New accounts rarely have that. The fix isn't to wait or to flood the campaign with budget hoping conversions appear - it's a deliberate 90-day plan that uses micro-conversions, manual control, and a phased migration into Smart Bidding once the data is real.

Why this matters - the algorithm needs signal

Target CPA, Target ROAS, and Maximise Conversions are all machine learning systems. They need conversion events to learn from. Below roughly 30 conversions per month per campaign, the algorithm is making bid decisions on too little data - results swing wildly, CPA spikes, and you can't tell whether the strategy is working or just lucky.

The temptation is to switch to Smart Bidding anyway because Google nudges you that way at every step. Don't. Switching too early in a low-data account can burn through a month's budget producing inconclusive results.

Days 0-30: Manual CPC + micro-conversions

Start with Manual CPC or Maximise Clicks (with a max CPC bid cap). Your goals in month one:

  • Confirm conversion tracking actually works end-to-end
  • Build a baseline of CTR, CPC, and CVR by campaign and keyword
  • Identify which keywords drive clicks (and which drive wasted spend)
  • Set up micro-conversions to give the algorithm more signal earlier

What counts as a micro-conversion

Anything correlated with a real conversion but more frequent: 60-second time on page, scroll depth past 75%, phone number click, "view pricing" page view, add-to-cart, contact-page view. Configure these as Secondary conversions in Google Ads - tracked but not optimised against (yet).

Days 30-60: Maximise Conversions (cautiously)

Once tracking is solid and you have at least 10-15 real conversions in the last 30 days, switch one campaign (your best-performing one) to Maximise Conversions without a Target CPA. This gets the algorithm started without locking you into a CPA target it can't hit.

Watch:

  • CPA - it will fluctuate; that's normal in the first 14 days
  • Search terms - the algorithm will probably explore broader queries; add negatives ruthlessly
  • Daily budget pacing - Maximise Conversions can blow through your budget early in the day

The single most useful thing in month two

Run a search terms report weekly and add 20-50 negative keywords each week. Smart Bidding can't un-learn bad search terms unless you tell it not to bid on them.

Days 60-90: Target CPA or Target ROAS

By day 60 you should have 30+ conversions in the last 30 days if the campaign is healthy. Now you can move to Target CPA (for lead gen) or Target ROAS (for eCommerce).

Set your target slightly above (10-20% higher CPA, or 10-20% lower ROAS) the actual average you achieved with Maximise Conversions. Smart Bidding doesn't hit aggressive targets out of the gate - giving it a realistic target lets it stabilise faster.

Once stable for 2-3 weeks, tighten the target by 10% increments. Each change resets the learning period for 7-14 days, so don't change it more than every 2 weeks.

When to use Portfolio Bid Strategies

If you have 3-5 small campaigns that individually don't hit 30 conversions/month but collectively do, group them into a Portfolio Bid Strategy. The algorithm learns from the pooled conversion data while still respecting each campaign's budget and targeting.

Find it: Tools > Shared library > Bid strategies > Portfolio.

The mistakes that wreck new accounts

  • Going to Target CPA on day one with no data
  • Setting a target CPA half of what the market actually pays - the algorithm just won't spend
  • Changing bidding strategy every week - each switch resets the learning period
  • Counting every form submission as a conversion without quality filtering
  • Using broad match on a new account with no conversion data to train it

Frequently asked questions

How many conversions do I really need before switching to Target CPA?

Google says 30 in the last 30 days. In practice we wait for 30-50 stable conversions before moving to a target-based strategy. Below that, you're asking the algorithm to make bid decisions on noise.

Should I run Maximise Conversions or Maximise Clicks first?

If conversion tracking is solid and you have any conversions at all, Maximise Conversions. If conversion tracking isn't yet reliable, Maximise Clicks (with a max CPC bid cap) until you can verify it.

Is "enhanced CPC" still worth using?

Enhanced CPC is being deprecated by Google. New campaigns are pushed straight to Maximise Conversions. Existing eCPC campaigns will keep running but for new launches, skip it - it's a dead end.

What if my industry has very few conversions ever (high-ticket B2B, real estate)?

Use micro-conversions as your primary signal early on - calendar booking views, pricing-page visits, demo requests. Then layer in the real conversion as a Secondary action with a higher value. Smart Bidding can optimise on micro-conversions if real-conversion volume is too low.

How long does Smart Bidding take to "learn"?

Google's official learning period is 7 days, but practically expect 2-4 weeks for the algorithm to stabilise after any meaningful change (new bidding strategy, new target, big budget change). Don't evaluate performance inside the learning period.

Ready to put this into practice?

Book a free 20-minute strategy call and get tailored recommendations for your business - no obligation, no sales pitch.