Earlier this week IGN reported that info on the specific sales and revenue numbers of PC game digital download services are still hard to come by. Steam and Direct2Drive would only admit to year-over-year percentage increases without revealing things like specific revenue or unit sales numbers.

Now one developer of downloadable games is taking those services to task for the lack of sales info. In a press release today, James Brooksby, the studio head of UK-based doublesix said, "I do wish that all the platform owners would make their digital sales figures public. We feel this lack of transparency is hindering the development of these channels."

He added, "As a developer trying to decide which platforms to develop for, as well as what type of games to make, we're currently in the dark regarding real sales performance for digital platforms and that makes it increasingly difficult to make realistic plans. I'd like to see some kind of verified sales charts on all digital systems to encourage more developers to support these channels and to help make sensible investment decisions."

doublesix was happy to announce that their recently released PSN downloadable game Burn, Zombie, Burn has sold 70,000 units so far. That number was enough for the game to achieve doublesix's own sales target and they expect that it will ultimately reach "a significantly higher lifetime figure."