Google recently started proving Free Sms service via its Gtalk service. However, some seriously smart developers used the same service to make an iPhone app ‘Infinite SMS’. This $0.99 app became one of the top selling apps on the App Store within a month of release. The app allowed iPod Touch users to send free text messages aswell.
However, Google has now decided to block these 3rd party clients using its SMS service. Apparently the SMS service is experimental, and such dedicated apps bring way too many users to the service, something that Google isn’t prepared to handle.
For now, there goes your free SMS from iPhone. Given the thin margins and ad based revenue models of many web services, it is difficult to extend them. Remember, there are no free lunches.