Last week, the results of a hugely important Federal Communications Commission auction came out. The Commission was selling the rights to use re-purposed TV spectrum to wireless carriers, and T-Mobile spent $8 billion to buy far more spectrum than anyone else.

The spectrum being auctioned is particularly valuable low-band airwaves that work better in rural areas and indoors — two areas that T-Mobile has struggled with, compared to Verizon, which has long held the licenses to a large amount of low-band spectrum.

But a new analysis of the data shows that while T-Mobile might have spent far more than any other company in the auction, it wasn’t just a case of having a bigger purse. Spectrum was sold in seven 10MHz bands, and each band was available for a particular region. For example, T-Mobile could have bought Band G for use in Washington DC, but AT&T could have bought the rights to the same band in New York City.

Overall, T-Mobile spent nearly $8 billion to buy 1,525 licenses. AT&T spent just $910 million, but only acquired 23 licenses. As Fierce Wireless pointed out, that brings AT&T’s per-license spend to nearly $40 million, while T-Mobile spent just $5.2 million per license.

A lot of that difference is probably down to geography. As you can see from the maps from Mosaik included below, T-Mobile bought spectrum in every single market across the country, including a lot of rural areas that were less valuable. AT&T focused its spectrum buys around much more expensive areas, like the Philadelphia-DC metro area, Dallas, Seattle, and San Francisco.

Looking at the raw auction data from the FCC, this becomes even more clear. T-Mobile and AT&T paid exactly the same price in regions like New York, Chicago and San Francisco; the difference is that AT&T didn’t even bid on spectrum in Wahpeton, ND, where licenses were sold for $5,000.

But on a strategic level, it’s still likely that history will show T-Mobile as the big winner from this auction. AT&T only invested in spectrum in urban areas where it already owns bandwidth, seeing it as a short-term way to alleviate network congestion. But in cities, spectrum is less likely to be a big deal in 20 years: solutions like LTE-U and Wi-Fi hotspots, deployed every couple hundred meters and inside buildings, are going to be the only way to handle overwhelming growth in the number of internet-connected devices.

So, AT&T paid through the nose for a short-term fix to network problems. T-Mobile, on the other hand, bought up new spectrum nationwide, in many cases in regions that are under-populated, and bought most of that spectrum for dirt-cheap. Just think about how Verizon is able to be competitive these days: it can charge a higher price for a network that’s only superior because of spectrum licenses it bought decades ago. In 20 years, AT&T might find itself ruing the day it decided Wahpeton, ND wasn’t worth $5,000.

Chris Mills has loved tinkering with technology ever since he worked out how to defeat the parental controls on his parents' internet. He's blogged his way through Apple events and SpaceX launches ever since, and still keeps a bizarre fondness for the Palm Pre.