T-Mobile smartphones are data beasts, eating up 760 MB a month

T-Mobile USA has a well-deserved reputation for having some of the highest volume smartphone users on the mobile Internet. Not only does it have the fastest 3G networks and the most liberal data caps in the industry save Sprint(s s), T-Mobile lets you user your phone’s mobile hotspot capabilities on mid-tier plans free of charge, allowing your typical user to actually consume the data he or she pays for.

T-Mobile this week revealed just how much that typical smartphone user on its network consumes: 760 MB per month. What’s more subscribers that have its 42 Mbps dual-carrier HSPA+ phones such as the new HTC One S gobble up an astonishing 1.3 GB a month, which proves the obvious: faster networks mean more data used. T-Mobile CTO Neville Ray revealed these details at the NGNM conference in San Francisco during a slide presentation (pdf) that was first reported by the eagle-eyed folks at FierceWireless.

Those figures may not seem huge to GigaOM readers, whom I’m betting tend to be power users. But let’s put those numbers in perspective. Cisco Systems’ Visual Networking Index calculated the average U.S. smartphone in 2011 consumed only 201 MB per month. Globally, Ericsson’s(s eric) Traffic and Market Report found that in the first quarter iPhones(s aapl) and Android(s goog) devices consumed roughly 350 MB per month. T-Mobile’s typical user either doubles or triples those numbers depending on which report you go by, and its power users break the bank completely.

It’s possible that Sprint’s average smartphone usage exceeds T-Mobile, but I doubt it. Sprint does still offer unlimited plans, but a large portion of its smartphones are on its CDMA network, not its soon-to-be-retired WiMAX service. Just as faster speeds increase data consumption, slower speeds limit overall data use. Plus Sprint doesn’t extend free mobile hotspot capabilities to its customers, meaning subscribers are limited to the data they can access directly from their phone screens.

We won’t know, though, until the carriers release information on their average usage rates, which they are loathe to do (in fact, I’m surprised T-Mobile did so). Carriers typically keep that data confidential because if it were it public, it would be glaringly obvious how much we’re getting ripped off. While it’s hard to argue with Sprint’s unlimited policies, AT&T(s t) and Verizon(s vz)(s vod) both have historically priced their data tiers in ways that nowhere near reflect how the typical smartphone behaves.

According to Chetan Sharma Consulting, only 30 percent of U.S. smartphone subscribers exceed 1 GB each month, yet their most common tiers are 2 GB and 3 GB plans. American consumers are paying for a lot of data that they couldn’t possibly consume. Verizon is rectifying that situation, in part, with new shared data plans that scale down to 1 GB a month, but it’s making up the difference by charging customers for required unlimited voice and SMS plans – arguably robbing Peter to pay Paul.

So why is T-Mobile releasing its numbers all of sudden? Well, for one, it has a lot less to be embarrassed about. Though its customers are still well below their caps, T-Mobile customers pay a lot less for data are consuming much more of the allotment they pay for. Also, T-Mobile is trying to convince regulators to nix Verizon’s proposed acquisition of the cable operators’ spectrum. Its key argument is that Verizon is a lousy steward of the public airwaves. By showing just how much its subscribers consume over the limited spectrum resources it owns, T-Mobile is betting it can shame Verizon in front of the Federal Communications Commission.