The New York Times writes in the context of the recent buyouts of Internet companies by media companies:
The media companies’ interest has to do with the continuing shift in the ways Americans consume entertainment and shop. Just as the advent of cable television carved up a once-concentrated block of network TV viewers, so has the Internet with its literally millions of Web sites created highly fragmented niche audiences.
For big companies, the key is to build or buy Web sites that attract those niche audiences, but in substantial numbers. For a Web site to pique the interest of mass-market advertisers, it needs to have at least a million unique visitors a month; to be considered a major takeover candidate, it needs to have five million unique visitors, said Sharon Wienbar, a managing director with BA Venture Partners, a Silicon Valley venture firm that invests in Internet content companies.