A Washington Post vending machine is stocked with newspapers for sale on May 1, 2009 in Washington, D.C. - 

The Washington Post is erecting a paywall or “paymeter” as it’s being dubbed. You get to read 20 free articles a week, but after that, you have to subscribe. It’s one in a long list of newspapers that are trying this business model.

And you know why, right? Everybody is reading news online and that means, the newspaper’s traditional source of money  -- print advertising -- has been drying up. Online ads haven't made up for the difference.

And the Washington Post is no exception, said Andrew Beaujon, who covers the media for Poynter Institute.

“The newspaper has had a rough couple of years, it’s lost a lot of staff, it’s lost a lot of money,” he says.

And so the paper is following the lead of the New York Times and other smaller papers by putting up a paywall, says Paul Sweeney, a media analyst for Bloomberg Industries. He says the results have been mixed.

The paywall for the newspaper industries has really been a case of the haves and have-nots,” he says.

The “haves” serve a national audiences like the Wall Street Journal and The New York Times. The "have-nots"? Local and regional papers. The Post falls in between. But Poynter's Beaujon says paywalls aren’t a silver bullet.

I think anyone who thinks a paywall is going to save a newspaper is kidding themselves,” he says. He adds newspapers still need find other ways to make money.