The deal comes as Motionbox has seen its traffic rise sharply over the year. The site, which claims about 2.8 million members, benefited when AOL (NYSE: AOL) closed down its own video service and suggested that users transfer their files to Motionbox instead. The company also purchased competing video sharing site Viddyou in October and added that site’s users to its own roster.

HP, however, seems more interested in Motionbox’s technology than in its audience; it’s shutting down the Motionbox site effective Aug. 10 and says all clips will have to be downloaded from the site by then.

Motionbox’s basic service was free, although it charged users $39.99 a month for premium accounts, which included unlimited storage space. (Snapfish Home Videos charges $24.99 a year). The company also had a hosting service for businesses.

Terms of the deal were not disclosed; Motionbox had raised nearly $17.2 million since its launch in 2006 from investors including Constellation Ventures, Canaan Partners and SAS Investors.