According to new data published by FierceWireless and the NPD Group, it looks like iPhone owners use more data than their Android counterparts. How was this data collected? NPD’s SmartMeter app was installed on roughly 1,000 smartphones. They’ve been collecting data from Android users since April 2012, but last month they started gathering data from around 100 iPhone owners. Translation: Their sample size for iPhone users is decent, but still one tenth that of Android users.

Here’s what the data shows: On Verizon, America’s largest operator, an average Android user consumed 0.57 GB of data in September. An average owner of an iPhone however, they consumed 1.58 GB. Moving on to AT&T, the operator who has been selling the iPhone the longest, their average Android user used 0.89 GB of data in September, whereas an average iPhone owner used 1.35 GB of data.

So why are there such huge differences? We want to say that it’s because Android smartphones are often purchased by people looking to upgrade their dumbphones, and that such people, the mainstream, typically don’t use all the features of their device, but the data support that conclusion. Apple’s iPhone holds a roughly 50% market share in the United States, making it anything but a niche device.

Maybe it’s because iPhone owners sign up for more expensive data plans knowing full well that they’re going to use up all the data they paid for?

Again, we don’t know really have a concrete explanation for these numbers. What we do know however is that the data gathering could and should be improved. If the iPhone represents 50% of the American smartphone market, it’s disingenuous that just 10% of the sampled audience uses an iPhone.

Oh and as for the one exception to the rule, it’s T-Mobile customers. Since T-Mobile is only now starting to support the iPhone’s 3G radios, it shouldn’t be a surprise that during September an average iPhone owner used only 0.19 GB of data. That’s nothing compared to 1.09 GB on average for an Android user.