How Do You Set a Target ROAS Without Starving the Long Tail?
Target ROAS is the most misused setting in Google Shopping. Google's target ROAS documentation says what it does plainly: you give the bidder a return goal and it bids to hit that goal on average. The trap is what happens under the average.
Set the target too high and the bidder does the easy thing. It pours budget into the handful of products and searches it already knows convert, and quietly stops bidding on the rest. Your reported ROAS looks great. Your coverage of the long tail collapses. Revenue flattens while the dashboard says the account is healthy.
So we do not run one target across the whole catalogue. Each margin tier gets its own, worked out from the real margin on those products, not from a number someone heard was good. Break-even ROAS is 1 divided by your gross margin. A 60% margin product breaks even around 1.7. A 12% margin product needs about 8.3 before it makes you a cent. Point the same target at both and you either burn the thin one or leave the fat one under-bid.
Then we move slowly. Target changes go in small steps, and never in the middle of a learning period. Google's own Smart Bidding help says a significant change restarts that clock. Restart it every week and the account stalls for a month with nobody noticing. Between changes we watch impression share and how many distinct products still got clicks. If that product count is shrinking, the target is too tight, whatever the ROAS number says.




