Amazon.com ( AMZN) is finally rolling the video. The e-tailer's much-anticipated video-download service, Amazon Unbox , finally debuted Thursday. It offers downloads of movies for $9.99 to $14.99 and episodes of television series for $1.99. Investors see digital media as one of the few potential bright spots for Seattle-based Amazon, whose shares have tanked almost 37% this year amid concerns about growing costs and rising competition. Amazon rebounded in August, jumping 17% as investors bet that the company would benefit from strong holiday sales. The stock dropped $1.07 to $29.73 Thursday. Video downloads seem to be a sensible move for Amazon, which is already one of the largest sellers of DVDs and also owns IMDB , a popular film and television information site. Wall Street analysts, who have questioned other Amazon moves, such as entering the low-margin grocery business, also have seen this as a potentially positive development. Still, it's unclear how big the demand will be for Amazon Unbox. The existing movie-download sites haven't yet attracted a huge following. Plus, it's been widely reported that Apple ( APPL), which already has the lion's share of the digital media market, is in talks with the movie studios to also offer movie downloads. iTunes already sells episodes of television shows and short films. Though initial media reports indicated that Amazon would also offer music downloads, Amazon Unbox only offers video content from studios including Viacom's ( VIA) MTV Networks, General Electric's ( GE) NBC Universal and News Corp.'s ( NWS) 20th Century Fox. Details of Amazon Unbox were previously reported by the Associated Press.