Explain a drop in conversion after a traffic surge

Separate a traffic-mix shift from a broken funnel.
Break the change into groups
A campaign sends 1,000 visits at 4% conversion. Adding 1,000 research visits at 1% raises orders from 40 to 50 while lowering overall conversion to 2.5%. The original traffic did not get worse in this example.

Check rates within stable segments
Compare device, source, and landing intent before and after the surge. A broad fall within each segment points to a different problem from a shift toward lower-intent traffic.
Decide whether the new volume was useful
Compare incremental contribution and acquisition cost for the new visitors. Check whether they help at a later stage before deciding from the blended rate alone.
Try a related tool
Find the share of eligible visits that completed a defined action. Count at most one conversion per visit for this calculation.


