Beginning this week, the digital arm of the New York Times Company has begun experimenting with premium content on its Web sites, beginning with a baseball newsletter from Boston.com and its online crossword puzzles.

Boston.com, which is published by New York Times Digital (NYTD), has just launched the @bat Insider e-mail newsletter for Red Sox baseball fans at $14.95 for the season.

NYTD, which has been charging $9.95 a year for its premium crosswords package, has hiked the price to $19.95, and plans to use the additional puzzle offerings as a "teaser" to lure crossword fans into purchasing annual subscriptions.

NYTD director of business development Ira Silberstein told atNewYork the plan is to tinker with subscription-only offerings for highly-specific, niche content.

"I want to make it clear our NYTimes.com Web site will remain free. Making that a premium product is not a viable business model. We're not interested in that. The premium products will be an ancillary stream."

If the Boston.com @bat Insider experiment picks up steam, look for the NYTD to implement similar e-mail newsletters targeting all kinds of audiences.

The company already has about 16 million e-mail addresses (subscription is required to read the NYTimes.com free content) and Silberstein said the database of users would be used to market the premium offerings.

He declined to comment on specific plans for premium newsletters but hinted that the experiment could begin with the next three months. The company already publishes several free e-mail newsletters but Silberstein believes the company can leverage its core of editors and journalists around the world to create niche content.

"Our paid products will be exclusive, timely and relevant. We're also working towards offering different price points for access to our archives. So, there are a lot of things coming down the pike."