How do you spot a ROAS mirage?

You spot a ROAS mirage by isolating branded traffic from the rest of your account. Move branded queries into dedicated brand search and shopping campaigns, remove brand terms from Performance Max, and look at the ROAS of the remaining non-branded activity. If non-branded ROAS is far below the blended number, the account is harvesting existing demand, not acquiring new customers.

When should you rebuild Google Ads structure rather than optimise incrementally?

Rebuild when budget increases collapse ROAS, when Performance Max consumes most spend without acquiring new customers, and when expansion into new geographies or product lines fails despite a healthy blended ROAS. Incremental optimisation works on a sound structure. It does not fix a structure that hides weak acquisition behind branded conversions.

How do Seasonality Bid Adjustments work in Performance Max?

Seasonality Bid Adjustments are a Google Ads feature that tells the algorithm to expect a temporary conversion-rate change for a defined window. For Black Friday, Get Lead set a 30% lift during the promotional period and a 30% drop the week after Cyber Monday. The algorithm pushes harder when intent is highest and pulls back automatically once demand cools, preventing post-promo overspend.