Nearly 5 million consumers have downloaded the latest version of the Skype iPhone app that allows VoIP calls to be made over 3G mobile networks since its launch on Sunday, the company said this week. Although the app has been available for a over a year, the earlier version only allowed Skype calls to be made over Wi-Fi networks. Russ Shaw, Skype’s general manager for mobile, told Reuters that its latest app saw a good mix of demand across Skype’s three main operating regions: Europe, North America and the Asia Pacific region. “We’ve had millions of downloads to date,” he said. A Skype spokeswoman confirmed that the number of downloads was nearly 5 million by Wednesday morning US Eastern Time.

However, the report notes that Skype has faced complaints after it also said on Sunday that it would start charging for 3G calls between Skype users from next year. The strategy marks a shift in business model for the company, which had always made Skype-to-Skype calls free for subscribers whether the service was accessed via PC or mobile. Shaw said the company needs to start charging for the service so that it can fund the investments needed to ensure that the quality of 3G Skype calls stays high; he did not disclose specific pricing details. “We’re not going to want to price ourselves out of the market,” he said. “I can’t ignore the fact that consumers [currently] use us for free.” Apple is due to unveil the next version of the iPhone next week and Shaw said Skype would hope to support the new model.