Apple struck a chord with competitors and consumers alike when it launched the first iPhone. The device wasn't perfect, but it sold in droves and each successive version of the iPhone has sold exceptionally well. The device is one of the most popular smartphones on the American market, despite only having one carrier.

The popularity of the iPhone and the tendency of customers to actually use the smartphone for its intended purpose means that owners tend to consumer more data bandwidth than users of other devices. In fact, AT&T has threatened in the past to charge iPhone users who consume more data than it thinks they should more money, despite the fact that iPhone data plans are said to be unlimited.

AT&T may blame the huge number of iPhones that it sells for its data woes, but the company recognizes how important the iPhone is to its bottom line. The company has pledged to improve its network and in Q1 Apple reported sales of the iPhone doubled so the number of iPhones on the AT&T network will only increase.

Consumer Reports has published the results of research that it commissioned from a company called Validas. Validas is a web firm that analyses the bills of wireless users that the customers willingly upload and the data is used for research when the providers won’t give first party numbers.

According to the data Validas provided Consumer Reports, the average iPhone user consumes 273MB of data per month. By comparison, the average Blackberry user only consumes 54MB of data each month. Users of other smartphones consume an average of 150MB per month. The data also showed that 12% of iPhone users gobble up 500MB per month of bandwidth and the biggest consumers of bandwidth using the iPhone use over 1GB of data per month.

Consumer Reports reached out to AT&T for first-party numbers and were turned down. An AT&T spokesperson said, "For competitive reasons, we do not disclose the usage of our iPhone customers."

The data analyzed by Validas included 757 iPhone users, 783 Blackberry users, and in total looked at 14,000 wireless users.