Jeremy Liew, a venture capitalist at Lightspeed Venture Partners, is quoted in the New York Times saying It takes 200 million monthly pageviews to earn $50 million a year on advertising supported sites. A site aimed at a specific demographic, like teenagers or Asian-Americans, would need to generate 800 million page views a month, by Mr. Liew’s reckoning.

And for a general-interest site, the ad rates go even lower, so traffic would need to be much higher to generate $50 million — about four billion page views a month, which would put it in the top 10 of all the sites on the Web.

This jives with what I heard this week at the MIT Enterprise forum; there is still a long way to go before they start paying the kind of rates they pay to traditional media outlets. It’s good to hear there is plenty of room out there for “lifestyle companies” servicing high-yield niches, thanks to advertsing programs such as Google AdSense. Not everybody wants to deal with growing a site to such enormous proportions, given the infrastructure and support required to run a high volume website.