Mary Meeker's 2012 "Internet Trends" presentation also serves as the basis for this post -- there may be a few more to come. It really is a great presentation, and worth going through. Anyhoo...
I've talked in some recent posts comparing the value of eyeballs on traditional media to new media.
Below are a few screenshots from Ms. Meeker's presentation, that I think further support my overall point (or, maybe, I actually support hers? Kind of hard for the completely obscure anonymous netizen to claim support from a titan of online industry...)



I still argue that online ads, when properly done, can be more valuable than offline ads, because they can actually be targeted to consumers. Of course, I also say this as someone who very rarely clicks on online ads. But then again, I also never really paid attention to TV ads, so I don't think I'm the target consumer. In any event, online advertising provides many more meaningful ways to actually connect with users than offline advertising ever did, and, as it evolves, traditional media outlets will be able to take increasing advantage of this phenomenon. So the money isn't going away, it's just moving around.