The channel credited with a first purchase may not be the channel that created the relationship. A buyer can encounter a brand in several places, click a search advertisement at the end and later return without clicking anything paid.
That makes repeat purchase a useful addition to acquisition reporting. It does not make attribution unnecessary. It changes the question from “Which platform claimed the order?” to “What happened to the customers associated with this activity?”
Google’s September 2026 measurement discussion describes attribution, incrementality and marketing mix modelling as different tools. As advertiser-platform guidance, it is context for designing a test, not independent proof that a particular Indian merchant should increase spending. Source.
Compare customers on the same clock
WCRC would begin with a cohort: customers making their first purchase during a defined period. Compare subsequent behaviour over the same length of time. Otherwise, older customers have had more opportunity to return than those acquired last week.
The calculation should remove cancelled and refunded orders and use a consistent customer identifier. Revenue alone can flatter a channel that attracts heavy discount users or costly returns. Contribution after fulfilment provides a different, often more useful view.
Powerful Brands’ Consumer Trust & Sentiment dimension offers a related analytical question: does the experience give customers a reason to choose the brand again? A repeat transaction is one behavioural signal. It cannot, by itself, explain trust or establish a WCRC score.
Use the result to design the next test
A channel with strong repeat behaviour deserves investigation, not an automatic budget increase. Its customers may differ in geography, product preference or purchasing power. The business must consider those differences before attributing the outcome to advertising.
Where practical, a planned experiment can test what changes when spending changes. A cohort report can help choose the question and measure its commercial consequences. Neither tool should be used to promise a result before the comparison is complete.
The merchant-level story remains to be reported. Its evidence would include spend, customer cohorts, returns and the attribution window. Until those records exist, the defensible output is a measurement method, not a claim that one channel has won.