Shareholders of Cablevision Systems Corp. (NYSE: CVC) must be scratching their heads over the company's $650 million purchase of Newsday from Tribune Co., the latest in a long series of baffling moves by the Dolan family, which controls the New York-based cable company.

The theory -- if you want to call it that -- is that Cablevision would be able to market the newspaper to its customers and that the company would be able to add additional content to its cable news channel. This makes no sense. People have stopped reading newspapers in droves. The only way that they would even consider subscribing is if Cablevision practically gave the newspaper away. Newsday could have struck an alliance with the cable channel to share content without the paper changing hands; these sort of deals happen all of the time.

Maybe advertisers will be more interested in Newsday now that Cablevision will be able to bundle ad space in the paper and its website along with cable commercial time. The problem, though, is that residents in Long Island have a plethora of media choices including the New York Times, New York Daily News and The New York Post. Like the readers, the only way that advertisers that aren't in the newspaper now would consider doing business with Newsday would be with steep discounts.