That's an interesting article. And it rebutts the point the blogga was making:

Entitled Three ways to build an online media business to $50m in revenue, the article does the math: At the $1 RPM (CPM/CPA/CPC) level achieved by most general sites, you need 4 billion page views/month. At the $5 RPM level achieved by demographically targeted sites, you need 800 million/month. At the $20 RPM level achieved by highly targeted sites, you need 200 million/month.

That's a high bar. This may be why more entrepreneurs are going for low-investment sites that don't need an exit but provide "lifestyle businesses" for their owners. (More on that another time.)

Who needs $50 million?? I don't. (I, unlike the original article's author, am not a VC.) Hell, gimme $5-6 million total and I'll be delighted.

Then again, there are a lot of untapped, underserved niches. Most of the Web2.0 sites, in my estimation, are nerd-oriented. There is plenty of room to serve more 'mainstream' niches (yes, I see the irony in that phrase).