Microsoft's forthcoming Windows Mobile Marketplace (or is it Windows Marketplace for Mobile? Microsoft uses both names) is the company's answer to Apple's App Store. But in order to prevent a repeat of the roadblocks hit by aspiring iPhone app moguls, developers should read the PDF listing Microsoft's banned dirty dozen on apps for the marketplace.
Some of the bans, such as apps that link to alternate app stores, are no surprise. But Rule No. 4 bans "applications that enable VoIP (Voice over IP) services over a mobile operator network." That means no Skype for Windows phones.
Rule No. 5 bans "applications that sell, link to, or otherwise promote mobile voice plans." Translation: Wireless carriers that sell Windows phones subsidized by service plans can't promote premium plans in the store.
Advertising is expected to pay for, or at least subsidize, many apps. But Microsoft has set the terms for ad content with Rule No. 6, which bans "applications that display advertising that does not meet the Microsoft Advertising Creative Acceptance Policy Guide." The guide bans audio, Flash, and even Microsoft's Silverlight streaming media format.
Other rules warn developers against uploading user data, including location. But there's one rule that should keep customers happy: All downloads must be kept under 10 megabytes.