CBS Corporation will acquire CNET Networks, the parent company of, and, among others, for $1.8 billion.

According to the announcement, with the acquisition of CNET's family of sites, CBS Corp. will now be one of the 10 post popular Internet companies in the U.S., with 54 million unique users each month.

The deal comes the day after CBS made its Upfront presentationto advertisers in New York in which they repeatedly stressed their ability to compete in the digital marketplace.

"CBS stands for premium content and unparalleled reach, and CNET Networks will add a tremendous platform to extend our complementary entertainment, news, sports, music and information content to a whole new global audience," says Leslie Moonves, president and CEO of CBS Corporation.

The purchase is an obvious nod to Internet moves made by CBS competitors in recent years, in particular the acquisition of MySpace by News Corp. (It's something of a breach of Upfront etiquette for CBS to announce big news on the day another network makes their presentation - notably, Fox is up today.)

The transaction is a cash tender offer for CNET shares at $11.50 per share. The CNET board has already approved the merger agreement, and the deal is expected to close in the third quarter of this