Your choice of Google Ads bidding strategy is one of the most consequential decisions in any campaign setup – and also one of the most misunderstood. Google’s default recommendations often push advertisers toward automated bidding before their accounts are ready for it, leading to wasted spend and disappointing results. This guide explains every major bidding option, when each one makes sense, and what to watch out for.
The Two Categories: Manual vs Smart Bidding
All Google Ads bidding strategies fall into one of two camps: manual bidding, where you set the maximum you’re willing to pay per click, and smart bidding, where Google’s machine learning adjusts bids in real time based on signals like device, location, time of day, and user behaviour.
The case for manual bidding: full control, no reliance on conversion data. The case for smart bidding: Google’s models process billions of signals no human can track. The catch? Smart bidding requires data to work – typically at least 30–50 conversions per month, per campaign, before the algorithm has enough to make good decisions.
Manual CPC
Manual CPC (cost-per-click) lets you set a maximum bid for each keyword. You can pair it with Enhanced CPC (eCPC), which allows Google to raise or lower your bid by up to 30% based on the likelihood of conversion.
Best for: New accounts with little to no conversion history, or experienced advertisers who want granular keyword-level control. Also useful for brand campaigns where bids are predictable and volume is limited.
Watch out for: Manual CPC requires active management. You’ll need to adjust bids regularly based on performance data, and it doesn’t adjust for real-time signals the way smart bidding does.
Maximize Clicks
Google spends your budget to get the most clicks possible within your daily limit. You can optionally set a maximum CPC cap.
Best for: Awareness campaigns or new sites where you’re simply trying to drive traffic. Can also help gather initial data before switching to conversion-focused bidding.
Watch out for: Clicks and conversions are not the same thing. Maximize Clicks will cheerfully drive high volumes of low-quality traffic if you’re not careful. Always set a maximum CPC cap and review your search terms regularly.
Target CPA (Cost Per Acquisition)
You set a target cost per conversion, and Google’s algorithm adjusts bids to hit that target across all auctions. If you want to pay no more than £40 per lead, set a £40 Target CPA and Google tries to get you leads at or near that price.
Best for: Lead generation campaigns with consistent conversion values and enough historical data. Works well for service businesses where every lead is roughly equivalent.
Watch out for: Set your Target CPA based on what your account has historically achieved, not what you wish it were. Setting a Target CPA far below your historical average leads to drastically reduced impression share as Google becomes overly selective about which auctions to enter.
Target ROAS
Target ROAS (return on ad spend) tells Google to adjust bids to hit a specific revenue-to-spend ratio. Set it at 500% and Google aims to return £5 for every £1 spent.
Best for: E-commerce accounts with variable conversion values (different products at different price points) and strong conversion data – typically 50+ conversions per month at minimum.
Watch out for: Target ROAS is the most demanding of all smart bidding strategies in terms of data requirements. Too little data and the algorithm will be overly conservative, drastically limiting your reach. Start with a Target ROAS close to your recent historical ROAS and adjust in 10–15% increments.
Related reading: What Is a Good ROAS for Google Ads? (And How to Improve It)
Maximize Conversions
Google spends your full daily budget to get as many conversions as possible, with no constraint on cost per conversion. You can optionally add a Target CPA limit.
Best for: Campaigns with limited budgets where you want the algorithm to find conversions without constraining it. Also a good starting point before moving to Target CPA once data is established.
Watch out for: Without a Target CPA constraint, Maximize Conversions can chase high volumes of cheap micro-conversions (newsletter signups, PDF downloads) at the expense of high-value conversions. Make sure your conversion actions are correctly prioritised.
Maximize Conversion Value
Similar to Maximize Conversions, but optimises for total revenue rather than conversion volume. Requires conversion values to be passed into Google Ads (either static values or dynamic values from your checkout).
Best for: E-commerce campaigns where products have different prices and you want Google to prioritise higher-value sales. Pairs well with revenue-based conversion tracking.
Target Impression Share
Google adjusts bids to hit a target impression share – the percentage of eligible impressions where your ad appears. You can target the top of page, absolute top, or anywhere on the page.
Best for: Brand campaigns where you want to dominate for your own brand name, or competitive categories where maintaining visibility is the primary goal.
Watch out for: Impression share is a visibility metric, not a profitability one. This strategy can drive CPCs well above what’s economically rational if set too aggressively.
How to Choose the Right Bidding Strategy
The simplest decision framework for Google Ads bidding strategies:
- New account, no conversion data: Start with Manual CPC or Maximize Clicks with a CPC cap. Gather data first.
- 30–50 conversions/month, lead gen: Move to Maximize Conversions, then add a Target CPA constraint once stable.
- 50+ conversions/month, e-commerce: Test Target ROAS. Start close to your historical ROAS and adjust gradually.
- Brand keyword campaigns: Manual CPC or Target Impression Share.
- Budget is limited but variable: Maximize Conversions without a target – let Google use every pound efficiently.
The Common Mistake: Switching Too Often
Smart bidding strategies have a learning period – typically 2–4 weeks – during which performance can be volatile while the algorithm calibrates. The biggest mistake advertisers make is switching strategies every week when results dip. Give each strategy at least 3–4 weeks of stable conditions before drawing conclusions, and avoid making major changes (budget, creative, landing pages) during the learning period.
Final Thoughts
The best Google Ads bidding strategy isn’t the most sophisticated one – it’s the one matched to your data volume and campaign objectives. Start with what your account can support, move to smart bidding when you have sufficient conversion data, and always set targets based on historical performance rather than wishful thinking.
At Marquee, we regularly audit bidding setups for brands that are spending more than they need to – and the culprit is almost always a mismatched strategy applied before the account was ready for it.
Related reading: To understand how your bids interact with Quality Score in each auction, see our deep-dive on how the Google Ads auction actually works.
Want expert help with your account? See our Google Ads management service.