The drop in PS3-specific games is telling. At the Game Developers Conference in March 2008, Chris Eden, senior developer relations account manager at SCEA, said that games are added to the PlayStation Store as soon as they are approved. If all the games being finished and approved are also being published, then one suspects that few developers are building PS3 software for distribution through the PS Store.

Given the feeble software schedule for the PSP in the coming months, the rise of downloadable PSP games on the PS Store is intriguing. Perhaps Sony is exploring the economics of launching PSP games through both its online service and brick-and-mortar stores.

With prices ranging from $5 for the rhythm games Beats to $22 for LocoRoco, Sony is no doubt collecting data on how well these games sell -- data that could determine the best way to launch brand-new, full-scale PSP games as online downloads.

The XBLA Drought & Savior Originals

In the first half of 2006 Microsoft assured eager Xbox 360 owners that, despite appearances, more Xbox Live Arcade games were indeed coming. The dearth of games during that period is evident in the monthly release chart below.

The service began delivering several titles regularly in Autumn 2006, and accelerated in early 2007. Microsoft broadened its software offerings with the introduction of Xbox Originals -- a line of games for the original Xbox (e.g. Halo) -- in late 2007.

A bi-annual chart of game releases reveals a broader trend in Microsoft's XBLA offerings.

Including Xbox Originals, the number of titles published on XBL in the first half of 2008 is higher than in the first half of 2007. Even with a greater number of Xbox Original titles, the service has received fewer games in the past six months than in the second half of 2007. Although an imperfect analogy, Microsoft has maintained a robust release schedule in part due to Xbox Originals, much as Sony has padded its store with PSP games.

Last month Microsoft announced that it would be culling underperforming titles from the service according to an analysis of demo-to-full-game conversion, Metacritic review ratings, and other criteria. The slowdown in XBLA titles (as opposed to Xbox Originals) could be evidence that Microsoft is exercising more control over which titles may appear on its service.