When is a Paywall Not a Paywall?

On March 28, 2011, readers who go to the New York Times online site will be able to view 20 stories for no charge, but will be asked to subscribe after that level of usage. But readers who come to Times articles through links from search, blogs and social media like Facebook and Twitter will be able to read those articles, even if they have reached their monthly reading limit. For some search engines, users will have a daily limit of free links to Times articles. That appears to mean Google users, who appear to be limited to five articles a day.

So the paywall is going up, but uses can use Facebook posts and Twitter feeds to read stories people think are important, with virtually no limit.

That's a clever way to put up a paywall without risking a huge falloff in readership.

A Letter to Our Readers About Digital Subscriptions - NYTimes.com