The program delivers advertisements, compares shopping results and other offers to users' computers, and tracks their browsing habits.

WhenU cannot be installed without a user reading a disclosure screen and clicking "I accept" or "Next" to give consent, sometimes unknowingly.

This model is similar to previous software known as Gator from the company now known as Claria Corporation.

Lavasoft's Ad-Aware and Computer Associates' PestPatrol briefly de-listed WhenU as an adware target in February 2005.

WhenU was added back to Lavasoft's detection list a month later.