Total Roku hours streamed reached a record 1 billion in December, the company said. The number included both video and audio streaming. According to the company, 13.4 million active Roku account holders streamed 9 billion hours in 2016.

Roku’s active account base grew an impressive 46 percent year-over-year in 2016. Streaming hours rose an even more impressive 70 percent, while media and licensing revenues more than doubled, Roku founder and CEO Anthony Wood highlighted in a news release.

“The investments we are making in our platform to enable advertisers and content publishers to reach our rapidly growing audience are paying off, and we are still in the early stages of our capabilities,” he added.

Roku’s content library and paid and ad-supported line-up of OTT video streaming channels rose correspondingly, the latter to over 4,500, according to the company. Roku says it now offers its subscribers access to some 450,000 movies and TV shows.

Management’s aim is to see Roku emerge as the most popular TV operating system in the U.S. All told, Roku’s TV distribution models accounted for 13 percent of overall smart TV sales in the U.S. in 2016, according to IHS Technology market research, and that’s only two years into the program, management touted. The company said it also comprises 48% of active streaming players in the U.S. and had revenues of nearly $400 million in 2016.

Roku on Jan. 31 announced the launch of its beta Comcast Xfinity TV app.