Our thirst for mobile data is only getting stronger as smartphones get faster and more powerful.

This year, the average U.S. cellphone user consumed 1.2 GB of data per month, the New York Times reports, citing a study by mobile analyst Chetan Sharma. That's nearly double the 690 MB consumed by the average user a year ago.

Not surprisingly, Sharma attributed the growth in data use to faster 4G LTE networks and more advanced smartphones, which can handle increasingly larger images and videos.

More sophisticated apps with larger file sizes may also have played a role. Although Apple prevents users from downloading huge apps without a Wi-Fi connection, in September the company raised the mobile download size limit from 50 MB to 100 MB. Android devices don't have a size limit for app downloads over mobile broadband.

For AT&T and Verizon Wireless, everything's going as planned. Both carriers switched from unlimited data plans to tiered plans a couple years ago, with the eventual goal of extracting more money from customers. At the time, the carriers told users that they don't need so much data , while promising to investors that the shift would reap big rewards over time. "The tiered pricing will become more important as time goes on than it is today," Verizon CFO Fran Shammo said at an industry conference in 2011.

It's worth noting that AT&T and Verizon now offer unlimited text messaging and voice calls with their shared data plans, which are now mandatory for new subscribers. With tiered data plans, the two carriers are hoping to capitalize on the move from calling and texting to pure data consumption through apps like Instagram, Snapchat and Facetime. If mobile data use continues to grow at the current pace, it might only be a year or two before average users are exceeding their 2 GB or 3 GB monthly individual data plans.

It'll be interesting to see if underdogs T-Mobile and Sprint can capitalize on this trend. Both carriers offer unlimited data plans. T-Mobile in particular has made big strides with its "uncarrier" branding, winning over new postpaid subscribers. Unlimited data is seen as a security blanket now, but it could become essential as more users start getting pelted with overage charges.