You cant buy advertising to sell advertising..

False. I can think of multiple exceptions.

Let me give three. First some large companies (like eBay) which do not do a good job of figuring out where to advertise for themselves, and are willing to let affiliates scoop up margin instead of figuring it out. Second there are comparison shopping companies which buy ads to sell traffic, but with the trick being that the traffic is sold to multiple places. (This is actually a benefit to the consumer because it saves them having to look on multiple sites.) Third there are companies that collect enough information to deliver more targeted advertising than could have been delivered from the original spot the ad was placed. An example of this is Campus Explorer.

I personally know people who are making money with all of these approaches. Details differ widely. However the commonality is that if you're getting into this type of business, execution matters a lot. You are explicitly trying to live off of the difference between your ability to buy advertising and someone else's ability to do the same. So unless you can execute better than them, and better than your competitors, you're going to quickly find yourself losing money on every transaction. Which is the fate of most who try this approach.

Yeah, sound like 1999.

To me, however, the biggest reason this is true is that if you have to push your website (or product) so much, it's because it sucks - and if it sucks, you have to be able to draw in a pretty high number of suckers who will pay a disproportionate amount of subscription money for the kind of service you're offering, as for example happens with online dating services...