WhenU - Ads by choice

WhenU has a n interesting business model: Allow users to voluntarily install a desktop application that serves them relevant ads.

"For example, when you are shopping for an air fare, WhenU recognizes this, and then provides you with an ad for a cheaper fare. The end result is an online experience that allows you, the consumer, access to more information and therefore make better informed decisions while saving money in the process."

Hm. I wonder how they'll make this compelling enough for people to download. Of course I have a silly SWA Ding! program running on my desktop (soon to be uninstalled)... With $35 million in funding, it looks like WhenU has some time to figure it out.