updated 12:55 am EDT, Tue June 7, 2011
Similar to Blackberry messaging, but free
The announcement of Apple's new iMessage service in iOS 5, which allows mobile device users to send MMS-like messages to each other for free, may have come as a surprise to wireless carriers, according to Daring Fireball's John Gruber and other sources. The service, which will work across both Wi-Fi and 3G, uses secure encryption and includes delivery receipts and optional read receipts -- rather a lot like Blackberry's proprietary Blackberry Messenger (BBM) service.
The new iMessage would not replace SMS or other forms of cross-platform messaging, as it is limited to just iOS devices that can run iOS 5, meaning the iPhone 3GS or later and the third- or fourth-generation iPod Touch. It would, however, cut down on the amount of profit carriers would get from the lucrative text-messaging market, which costs carriers next to nothing to provide. Under many plans, SMS text messages carry a separate charge, or are sometimes sold as a package add-on to other plans.
The iMessage service, built into the Messages app, would automatically determine if the recipient was using an iOS device and send the text, photos, images, videos, locations or contact information free of charge. Normal charges (if any) would continue to apply for messages sent to other devices. Conversations using iMessage can be kept in sync on multiple iOS devices that are all registered to the same owner.
Other third-party apps, like Whatsapp ($1), have offered the same sort of service across devices, and continue to compete as well as be an option for older iPhones and iPod Touch devices unable to run iOS 5.