Q: We were 'losing' 14% of conversions until we checked postback timing — what was the bug?

Q: We were 'losing' 14% of conversions until we checked postback timing — what was the bug?

A: A postback is the server-to-server signal that tells your tracker a conversion happened. Sometimes the conversions are real and the loss is purely a plumbing bug. One team lived this.

They saw 14% fewer conversions in their tracker than the advertiser reported paying. Before crying scrub, they logged postback timestamps and HTTP responses. The finding:
— 14% of postbacks were arriving but hitting a timeout because their endpoint took over 10 seconds to respond under load
— The advertiser's system retried only once, then gave up
— Those conversions were paid but never recorded on the affiliate's side, breaking their optimization data

They moved postback handling to a lightweight queue that responds instantly and processes later.

Result: the 14% gap closed to under 1%, and their optimization improved because they were finally seeing all winning placements.

Short version: a slow postback endpoint can silently drop conversions — log response times before assuming the network is scrubbing you.

Still stuck? Drop your case in the comments.