Amazon.com's popular movie information and trivia website IMDb.com is bulking up.

It's acquired Box Office Mojo, another popular site that tracks movie grosses and has gained a following among Hollywood insiders and film buffs. Variety notes the acquisition should "should enhance the relatively sparse box office data" on IMDb.

Terms of the deal were not disclosed.

A note on the Box Office Mojo site indicates the deal closed in July 2008. Movie analyst Brandon Gray, who founded the website in 1999, did not immediately return an email.

Box Office Mojo averages over 1 million unique visitors per month, according to the site.

IMDb, which stands for Internet Movie Database, was founded in 1990 by Col Needham, a native of Bristol, England, and acquired by Amazon for an undisclosed price in 1998.

It's become a go-to source for TV and movie info, with cast lists, photographs, trivia, reviews, celebrity biographies, and more.

IMDb boasts over 57 million unique monthly visitors.

An interesting side note: My colleague John Cook wrote today about an IMDb veteran, Barnaby Dorfman, who's launching a new community-based food web site, Foodista.

UPDATE: I just spoke to Keith Simanton, managing editor of IMDb, and Box Office Mojo founder Brandon Gray. They were short on specifics about the deal, but Simanson had a lot of praise for Mojo.

"Box Office Mojo has been fanatical and assiduous about getting info about box office (numbers) and it’s really hard to get it right," Simanton said.

He added: "There's a reason why Mojo is a destination site for studio execs."

Simanton said Box Office Mojo will continue to operate as a separate website but "we have plans for it which we can’t get into."

Box Office Mojo, a 3-person operation in Burbank, Calif., will remain in the Los Angeles area. IMDb has over 100 staff, spanning Seattle, the U.K. and other locations, Simanton said.