Depends what virtual good your paying for, more content in a game I'm spending a lot of time playing would be worth it, although I don't see myself liking any of the flash app games on that level.
Google ads can be useful from time to time, random ads not really, I think most of the random ads I click on are non purchase interesting looking things or ads for physical stores I know because they have a decent deal in the ad.
Beyond the examples of virtual goods and ads, my point is that I'm not necessarily a typical user which makes it sometimes difficult to grasp the way people work.
