Target ROAS (Return on Ad Spend) is a Google Ads Smart Bidding strategy where you specify the average revenue you want to generate for every pound spent on ads, and Google's AI automatically sets bids to achieve that target. For example, a Target ROAS of 400% means you want £4 in revenue for every £1 in ad spend. Google adjusts bids in real time — bidding higher for auctions more likely to generate high-value conversions, lower for auctions likely to generate lower-value or no conversions. Target ROAS is most appropriate for ecommerce campaigns where conversion values (order amounts) are passed to Google Ads.
Target ROAS is the preferred bidding strategy for most ecommerce campaigns because it optimises for revenue rather than conversion volume. A campaign optimising for conversion volume (Maximise Conversions) may generate many low-value purchases while missing higher-value opportunities. Target ROAS directs the algorithm to prioritise high-value conversions — users likely to spend more — even if this means winning fewer total auctions.
Target ROAS requirements and setup
- Conversion value tracking — purchase amounts must be passed to Google Ads via the conversion tag
- Sufficient conversion volume — Google recommends 50+ conversions per month within the campaign for reliable optimisation
- Set a realistic ROAS target — too aggressive a target (800%+) may result in very limited impressions and low traffic
- Learning period — allow 4-6 weeks for the algorithm to accumulate data before evaluating performance
- Avoid dramatic ROAS target changes — incremental changes (±20% at a time) allow smoother algorithm adjustment
- Monitor actual ROAS vs target — if consistently missing target in either direction, adjust the target rather than switching strategies
- Segment by product margin — products with different profit margins may warrant different ROAS targets
A 'good' ROAS depends entirely on your product profit margins. If gross margin is 40%, a minimum viable ROAS to cover ad spend is 250% (£2.50 revenue per £1 spent — at 40% margin, £1 profit per £1 ad spend). Profitable ROAS targets for 40% margin products are typically 350-500%+. For lower-margin products (25% gross margin), you need 400%+ ROAS just to break even on ad spend. Always calculate your minimum viable ROAS from your margin structure before setting a Target ROAS.
Target CPA optimises for a specific cost per conversion (acquisition) — appropriate when all conversions have approximately equal value (lead generation, app installs, sign-ups). Target ROAS optimises for a specific return on ad spend relative to conversion value — appropriate when conversions have varying values (ecommerce orders of different sizes). For ecommerce, Target ROAS is almost always preferable to Target CPA because it accounts for the varying revenue of different orders. For lead generation where all leads are treated equally, Target CPA is more appropriate.