The Associated Press reports that CBS Corp. (NYSE: CBS) is buying CNet Networks Inc. (NASDAQ: CNET) for $1.75 billion. This $11.50 a share deal is a 45% premium over Wednesday's closing price

CNet's Web sites include News.com, TV.com, Mp3.com, MySimon and GameSpot. And CBS expects to use CNet to tap into the Internet advertising market. This deal raises the question of whether any CBS competitors will decide to get into the game of buying Internet content companies.

Here are three possible targets:

• TheStreet.com (NASDAQ: TSCM) - This provider of business, investment and ratings content has $65 million in sales and a market cap of $236 million.
• TechTarget (NASDAQ: TTGT) - This provider of online content for buyers and sellers of corporate information technology (IT) products has $95 million in sales and a $531 million market cap.
• WebMD Health Corp (NASDAQ: WBMD) - This provider health information services to consumers, physicians and other healthcare professionals, employers and health plans has $332 million in sales and it's market capitalization is $1.7 billion

I think traditional media companies buying Internet ones could become a trend. It would only take two more such deals to make it one.

Peter Cohan is President of Peter S. Cohan & Associates. He also teaches management at Babson College and edits The Cohan Letter. He has no financial interest in the securities mentioned.

MOST NOTEWORTHY: SLM Corp, Tempur Pedic and ITT Corp were today's noteworthy downgrades:

• Morgan Stanley downgraded SLM Corp. (NYSE: SLM) to Underweight from Equal Weight citing the impact on earnings from reduced government subsidies and disrupted capital markets.
  
• Tempur Pedic (NYSE: TPX) was cut to Neutral from Overweight at JP Morgan citing the consumer slowdown and increased competition.
  
• Credit Suisse downgraded ITT Corp. (NYSE: ITT) to Neutral from Outperform citing the surprised management changes announced last night.

OTHER DOWNGRADES:

• Cowen downgraded TechTarget (NASDAQ: TTGT) to Neutral from Outperform.
  
• Merriman lowered Jamba (NASDAQ: JMBA) to Neutral from Buy.
  
• LSI Corp. (NYSE: LSI) was downgraded at Merrill to Neutral from Buy.

MOST NOTEWORTHY:

• Caliper Life Sciences Inc (NASDAQ: CALP) was initiated at Piper Jaffray with an Outperform rating and $8 target. Piper believes the company's collection of acquisitions offers a diverse portfolio targeting a $1.2B segment of the life science tools market.
  
• Credit Suisse resumed coverage of Network Appliance Inc (NASDAQ: NTAP) and EMC Corporation (NYSE: EMC) with Neutral ratings and a $28 target and $20 target, respectively, as they have concerns of near-term demand risk.
  
• Concur Technologies (NASDAQ: CNQR) was started at Jefferies with a Buy rating and $40 target, as they believe the company is changing the landscape of employee expense management by integrating travel and expense reimbursement and feels shares deserve a premium valuation.
  
• Oppenheimer sees limited upside from current levels at TechTarget Inc (NASDAQ: TTGT) and would consider an entry point in the low-to-mid teens. The firm started shares with a Neutral rating and $17 target.

• Banc of America initiated K Swiss Inc (NASDAQ: KSWS) with a Sell rating and $20 target.
  
• Stephens initiated Comverge Inc (NASDAQ: COMV) with an Equal Weight rating and $29 target and Badger Meter Incorporated (AMEX: BMI) with an Overweight rating and $39 target.
  
• JMP Securities resumed coverage of DemandTec Inc (NASDAQ: DMAN) with a Market Outperform rating and $16 target.