Google Ads bidding strategies compared — which to use and when.

You set the max CPC for each keyword. Full control, but requires constant manual adjustment. Best used for the first 4-8 weeks of a new campaign to gather data before switching to Smart Bidding. Don't stay on Manual CPC once you have conversion volume — you will lose to advertisers using automated bidding on the same terms.

Google maximises the number of clicks within your daily budget. No conversion optimisation. Use this to fill top-of-funnel traffic quickly or to gather conversion data. It is not a long-term strategy — it will find clicks regardless of their quality. Always set a maximum CPC cap to prevent overpaying.

Google spends your full budget trying to get as many conversions as possible, regardless of CPA. Use when you're moving off Manual CPC and have conversion tracking in place but not enough data for Target CPA yet. Add a Target CPA cap if budget is a concern — this prevents runaway CPAs while still giving the algorithm flexibility.

Set a target cost per conversion and Google optimises every auction to hit it. The single most effective strategy for lead gen when you have the data. Key: set your target at or slightly above historical CPA. Set it too low and impression share collapses. Allow 2-4 weeks of learning after any change.

Google optimises for a specific return on ad spend — e.g., 400% ROAS means $4 revenue for every $1 spent. Requires accurate revenue values in your conversion tag. The algorithm will prioritise high-margin products and audiences that have historically converted at higher values. Start with a ROAS target close to your actual historical average.

A hybrid that adjusts your manual bids up or down based on conversion likelihood. Google has largely moved away from recommending eCPC. If you're using it, consider moving to Target CPA or Maximise Conversions instead — they give the algorithm more room to work and typically deliver better results.