Why is my final search feed revenue lower than the estimated revenue?
Estimated revenue counts every click as it happens. Final revenue is what remains after the search engine's quality review removes invalid clicks, applies any pricing adjustments and credits advertisers. A small gap is normal. A large or growing gap is a signal that some of your traffic is being judged invalid or poor value.
Think of estimated revenue as a till roll and finalised revenue as the bank statement after refunds. The review looks for bot traffic, repeated clicks, abnormal patterns by source and clicks that never lead to an advertiser conversion.
If the gap widens, break it down by Channel ID and by Sub ID to find which traffic source, placement or creative is responsible, then cut it. Feed providers can sometimes say which channels were hit even when the engine gives no reasons. Independent scoring of visits, for instance a traffic quality score, helps spot the problem before month-end instead of after it.