If you want to be really wonky about newspaper paywall’s audience and revenue numbers, Harvard’s Nieman Journalism Lab has released a paywall simulation that let’s you play with revenue,  audience and subscription numbers. It’s a lot of fun if you know what the numbers mean.

Along the same line of thought, Newsday is three months into it’s paywall experiment charging $5 a week for access to their website (print subscribers and Cablevision Cable subscribers have free access) and they have 35 paid subscribers. In the three months since starting the experiment Newsday has lost over 50 percent of their web traffic peaking at 1.5 million visits per month in July 2009 down to 460,000 visits in December 2009.