New York / Shanghai -The New York Times announced yesterday that it would introduce a paywall for its website, which currently boasts the highest readership of any online news publication, with over 30 million unique visitors each month. The move was first floated over a year ago and is seen by many media experts as an inevitable first step toward creating a sustainable online news model.

The paywall, which will go into effect immediately in Canada and be rolled out worldwide on March 28, will charge $15 to readers who surpass 20 articles per month, but will remain open to readers who click through to the site from new media platforms such as Twitter and Facebook. Google links will also remain open. Readers who already have subscriptions for the newspaper will have full access to the site, and "Top News" will remain open on smartphone and tablet applications.

"While The Times (of London) created a paywall that completely blocked non-subscribers from the site, The New York Times' paywall is porous," said Adam Taylor, new media specialist and editor for Business Insider. "The New York Times is allowing more entry points - including, importantly, access from social media. When they get big stories, they will still get traffic."