Sony Computer Entertainment America CEO Jack Tretton has labelled Vitasales "acceptable". It's hardly a ringing endorsement of the system's performance, but the executive toldGamesIndustry.biz he isn't disappointed with the handheld's showing at retail."In this industry, you can't get too high or too low, because it moves very quickly," he said. "I think there's an acceptable number - and [the number] we've sold: That's acceptable. If it was triple that, I'd be happier. If it was one-third, I'd be disappointed. "Anything with great rewards is going to come with great challenges," Tretton added. "We felt if the tech was there, and the game support was there, then the audience would be there. ... I feel much better about it now than I did four months ago." Sony Computer Entertainment UK boss Fergal Gara said last week that the company "would love" Vita to be selling more, noting: "I think we haven't quite hit the spot with the killer software just yet and I have every reason to think that will happen in the next few months." And earlier this week Sony Worldwide Studios president Shuhei Yoshida admitted for the first time that the PlayStation business has an uphill battle convincing some publishers to commit to its next gen portable. http://www.computerandvideogames.com...ation-us-boss/