Stores with repeat buyers keep going back and forth on what the purchase conversion should send to Google. One camp says first-order revenue, so tROAS optimises for the customer you actually paid to acquire. The other says lifetime value through value rules or offline uploads, so the bidder rewards customers who come back.
I lean toward first-order for bidding and LTV for reporting. Take a supplement store where the first order only breaks even and the second and third carry the margin. Feed LTV into the bidder and it will pay more for every first purchase, including from people who never reorder, so your CPA on new buyers gets fuzzy. Keeping first-order as the bid signal keeps the target honest, and you judge cohort revenue separately.
Has anyone seen LTV value rules hold up when the repeat rate is low, or does it mostly just inflate the numbers?