The latest version of RIM’s BlackBerry App World has gone live this week offering in-app payment support for the first time. The new version of the storefront (version 2.1) allows developers to use RIM’s Payment Services SDK to enable in-app payments in future and existing applications. Vendors will be able to register and manage virtual goods through the BlackBerry App World Vendor Portal and a reporting feature will be able to track purchases/payments for their goods. In-app payments will be subject to the same revenue share splits as offered by the BlackBerry App World storefront and use the payment type users specify in their BlackBerry ID (which can be either a credit card, carrier billing or an online payment service such as PayPal).

BlackBerry App World 2.1 has been in beta mode since the beginning of the month and was widely expected to include the in-app payments feature. According to earlier reports, RIM changed its stance on the subject based on feedback it received during App World 2.0. By a quirk of timing, RIM’s announcement of support for in-app billing comes the same week as Google announced it is doing the same in its Android Market apps store.

Letting users download an app for free and pay later through an in-app purchase of additional content has proved successful in other app stores. It is credited as being a significant revenue generator for developers using the App Store. Remco van den Elzen,  co-founder of analytics firm Distimo, said in November last year that he believed in-app purchases now represent about 30 percent of all iPhone App Store revenue, in an interview with GigaOm Pro. The so-called Freemium model makes particular sense for games developers, enabling them to pay for new or exclusive levels and features.