
AdMob, a firm that supplies advertising services targeting ad-supported iPhone adds, says that between September 15th and 22nd, only 23% of devices running apps with AdMob adds had updated to iPhone OS 3.1. Nonetheless, they say this is "significant update" compared to other releases. 51% of devices exposed to AdMob ads are still running OS 3.0, and 19% are still running v2.2.1, while 7% are still running v2.0 or earlier.