With the new iPhone operating system, people will be able to send texts over their data connection for a much cheaper rate
Part of iOS 5, announced today, is a new version of iMessage, the iPhone's texting app. It's got a cunning twist -- messages sent from one iPhone to another do not use the cell phone network's standard SMS protocol. They use the 3G data connection instead, which means the user pays a data rate rather than a text message rate.
So what? Well a text message costs 20 cents to send or receive. (I'll be using AT&T as an example, though most of the carriers charge similar rates.) This only sounds remotely reasonable until you calculate how much data is actually in a text message, and how the charge compares to regular voice and data rates. After all, while we're charged differently -- very differently -- for them, text messages are just like all data that travels to and from a mobile phone.
While most text messages are much shorter, their maximum length is 160 characters, which means they're up to 160 bytes. Compare to a three-minute song, which is around four megabytes, or 25,000 times as much data. An average web page is 697 kilobytes, or 4,300 times as much data. A photo taken with the iPhone is around 1.2 megabytes, or 7,500 as much data. But when you send any of these over a cell phone carrier's network, you're using their regular data network.