I do not know anybody who clicks on pop ups or side bar advertisements – they use Amazon.com, go to the Apple store, whatever. This raises 2 possibilities:
2- internet advertising is a bubble
If 2 is the case, it raises an interesting problem. Many, many websites owe all/most their money to advertising (free news sites, Facebook, Google, etc.). Obviously, then, there is money to be made in advertising, but a very large number of "hot" start ups are designed to make advertising more efficient. These are the guys who will be in harm's way if there is a bubble and it bursts.