Symptom
The distortion lives in what last-click attribution cannot see: session count includes every initiated session regardless of whether a real user was behind it.
Cause
A portion of sessions are generated by bots or low-intent traffic — inflating totals without contributing any engagement or conversion signal.
Impact
Teams optimize toward inflated traffic signals and misallocate budget toward non-performing sources — making acquisition decisions against a denominator larger than the real user audience.