At the end of the day, the real problem with using ComScore #'s when developing a media plan is unlike with all other forms of mass media (TV/Radio/Print), in Online the advertiser has direct feedback from the audience of their advertisements - hence you don't really need to use a 3rd party measurement service to help you determine if your campaign was on target/"worked". A much better way to buy media online is spri…
I'm not in the ad game, but what you just said doesn't sound right to me. I mean, if I see 10 ads for a new show on TV network X, even if I don't click on them they have value. Not everything is monetizable online, and those things that aren't will be hard or impossible to track.
The key point I'm making is as an advertiser, there is no way for me to know that you saw those 10 ads on TV - hence the need for 3rd party measurement. On the web, I have a direct line of sight to you - hence why introduce a 3rd party?