Apple iPhone developers now have the option to offer in-app content purchases within free software; previously, such functionality was available only within paid applications.

The expanded capability was reported by Macworld, citing a screenshot of an iPhone Developer Program notice. It means iPhone developers finally have full access to the so-called "free-to-play" business model, most common in online PC games, which offers the base client at no charge and then generates revenue through microtransactions and advertisements.

Some iPhone developers are already seeing financial success through free games with ads alone: Amplified Games recently revealed it earns nearly $10,000 a month in iPhone game advertising revenue on average.

Soon after the news broke, Neil Young of iPhone game publisher Ngmoco said in a Twitter post that with in-app purchasing now open to free games, the company's upcoming microtransaction-based multiplayer shooter Eliminate will go free-to-play.

That announcement follows recent statements by Alan Yu, also of Ngmoco, expressing concern about iPhone piracy. Speaking at GDC China, Yu said Ngmoco's games have seen piracy rates of 50 to 90 percent in their first week of release, and that the average price of iPhone games is dropping across the board.

Apple likely took those developer concerns to heart with its recent decision: base game prices can't get any lower than free, and it's significantly more difficult to pirate microtransaction-based supplementary content than a simple game client.