The essentials
- Two families: manual bidding (you set the CPC) and automated Smart Bidding (Google optimises towards an objective).
- The decisive criterion: your conversion volume. Below 15 to 30 a month, automated strategies lack signal.
- The typical path: maximise clicks at launch, then maximise conversions, then target CPA or target ROAS once you have the volume.
- Prerequisite: reliable conversions, imported from GA4 with a value.
At every search, Google Ads runs an auction between advertisers. Your bidding strategy defines how your bid is set: by you, keyword by keyword, or by Google's algorithm according to an objective. That choice determines what your clicks cost, your conversion volume and your profitability. It depends above all on one figure: how many conversions your account produces each month, measured reliably.
The seven bidding strategies
| Strategy | Type | Objective | Recommended minimum volume | Who for |
|---|---|---|---|---|
| Manual CPC | Manual | Control over cost per click | None | Small accounts, tests, experienced advertisers |
| Enhanced CPC (eCPC) | Semi-automated | Adjusts your manual CPC by likelihood of conversion | A few conversions | The transition to automated |
| Maximise clicks | Automated | As many clicks as the budget allows | None | Launch, awareness, gathering data |
| Maximise conversions | Smart Bidding | As many conversions as the budget allows | 15 to 30 conversions / month | Lead generation |
| Target CPA | Smart Bidding | Conversions at a set average cost | 30 conversions / month | Leads with a known acquisition cost |
| Maximise conversion value / target ROAS | Smart Bidding | The most value, or a set return on ad spend | 30 to 50 conversions / month with a value | E-commerce |
| Target impression share | Automated | Appearing in X% of auctions, at the top of the page | None | Brand protection |
Since 2021, target CPA and target ROAS have been options within the "Maximise conversions" and "Maximise conversion value" strategies. How these algorithms work is set out in detail in automated Smart Bidding.
Choosing by objective
You're launching an account or a new campaign
Start with Maximise clicks with a CPC cap, or with manual CPC if you know what a click is worth. The objective is to gather data: which keywords generate conversions, and at what cost. Move to automated after 4 to 6 weeks and around thirty conversions.
You're after leads (quotes, enquiries, appointments)
Maximise conversions first, then Target CPA once you know what cost per lead you can accept. Set the target CPA slightly above the observed CPA, then lower it in steps of 10 to 15% every two weeks. A target CPA that is too ambitious all at once cuts your delivery dead.
You sell online
Maximise conversion value, then target ROAS as soon as the purchase event comes through with its value. Target ROAS lets you favour high-value baskets. A target ROAS of 400% means €4 of sales per euro spent; your break-even point depends on your margin (see ROAS).
You're protecting your brand
Target impression share at 90% absolute top of page on queries containing your name, with a CPC cap. It costs little and stops a competitor capturing your customers.
The role of GA4 data
Smart Bidding strategies are only as good as the conversions you feed them. Three rules:
- Import your GA4 key events into Google Ads (see connecting GA4 to Google Ads) rather than multiplying tags.
- Mark only conversions with business value as "primary". Optimising on an unfinished form click or on a page view steers the algorithm towards visitors who bring you nothing.
- Give a value to every conversion, even an estimated one for a lead, so you can move to target ROAS one day.
A false or duplicated conversion is automated bidding's worst enemy: the algorithm learns from noise. Your conversion tracking should be audited before any move to Smart Bidding.
Monitoring and adjusting
In Google Ads, the "Bid strategy status" column shows learning phases and limitations (budget, target). In GA4, the Advertising > Google Ads campaign performance report shows cost per key event and engagement rate by campaign: a strategy maximising conversions by bringing in visitors who leave at 20% engagement is optimising towards a badly defined conversion. The metrics to track on the Google Ads side are in which KPIs to judge your SEA provider by, and the GA4-side analysis in tracking your Google Ads performance with GA4.
How GreenRed helps
Rather than juggling several tools, GreenRed's Google Ads module brings these metrics together in a single dashboard, compares them over time and tells you which actions come first. You can try it free, with no card, from the Pricing.
Frequently asked questions
Which bidding strategy should I start with on Google Ads?
Maximise clicks with a CPC cap, or manual CPC if you know what a click is worth. These strategies need no conversion history and let you gather, within weeks, the data you need to move to an automated strategy.
How many conversions do I need to use target CPA?
Google recommends at least 15 conversions in the last 30 days for Maximise conversions, and around thirty for a stable target CPA. Below that, the algorithm lacks signal and performance is erratic. Group your campaigns into a portfolio strategy if each one is too small.
Target CPA or target ROAS: what's the difference?
Target CPA optimises for conversions at a given average cost, without distinguishing their value: suited to leads. Target ROAS optimises the value of conversions against your spend and favours high-value baskets: suited to e-commerce, provided every conversion comes through with its value.
Why does my performance drop after a change of strategy?
Every change triggers a learning phase of 7 to 14 days during which Google tests bids. That is normal. Avoid changing the strategy, the target or the budget by more than 20% during that period, and judge the results over a full 30 days.