uTorrent parent company BitTorrent Inc. just announced that the BitTorrent Mainline client and uTorrent have hit the milestone of 150 million monthly users. Together both clients increased their user base by more than 50 percent compared to last year, and the end of this surge is not yet in sight.

With millions of people using BitTorrent every day, the protocol has been the leading P2P technology from more than half a decade.

Despite massive competition from cyberlockers, BitTorrent continues to expand year after year, and not just by a little. Today, BitTorrent Inc. announced that their two flagship clients increased their user base by 50 percent, to more than 150 million active users a month.

Most growth can be attributed to uTorrent, which more than quadrupled its number of monthly users in the last three years. The ‘tiny’ BitTorrent client went from 28 million monthly users in December 2008 to 132 million last month.

“This marks an amazing milestone for our company and we want to thank our loyal users and partners for their support. Our protocol and software clients have become some of the most pervasive pieces of technology in Internet history,” says BitTorrent Inc. CEO Eric Klinker.

“We look forward to another exciting year of growth and we continue expanding our product lines to meet the needs of consumers creating and consuming high-quality personal media files on a broad range of consumer electronics devices,” he adds.

The last comment ties in to a slew of other announcements released by BitTorrent today. The company is currently showcasing several “BitTorrent Certified” devices at CES, the world’s largest consumer electronics tradeshow in Las Vegas. Through these partnerships BitTorrent hopes to add an extra revenue stream, and widen its user base beyond the traditional computer.

Aside from showing off BitTorrent-enabled routers, TVs and network storage devices, BitTorrent will also launch the world’s first certified set-top box developed by the Slovakian company Antik. The set-top-box allows users to search, download and play torrent files directly on their TV.

The advantage of the BitTorrent Certified ecosystem is that it simplifies the downloading process for less tech-savvy people. Right now, many people drop out after installing a BitTorrent client because they find it too complicated to download and play content.

Whether these devices will be a success is yet to be seen, but there is certainly a large enough user base to tap into.

Based on the 150 million active monthly users BitTorrent Inc. reports for their clients, the total number of monthly BitTorrent users can be estimated at more than a quarter billion. And despite these already dazzling numbers, there is still plenty of room for growth.