A video sign displays the logo for Roku Inc, a Fox-backed video streaming firm, in Times Square after the company's IPO at the Nasdaq Market in New York, U.S., September 28, 2017. REUTERS/Brendan McDermid

(Reuters) - Roku Inc ROKU.O shares were up nearly 7 percent premarket on Thursday after it posted smaller-than-expected first-quarter loss helped by its TV streaming platform.

Roku, which makes devices for TV streaming, said bit.ly/2ryHWAN on Wednesday revenue from its platform more than doubled to $75.1 million, from strong growth across advertising and content distribution.

“The strong growth in Roku Channel usage highlights growing ad-supported content consumption,” Morgan Stanley analyst Benjamin Swinburne wrote in a client note.

Roku also beat Wall Street expectations with active accounts up 47 percent to 20.8 million at the end of March 31 and average revenue per user jumping 50 percent, fastest growth rate in 18 months.

“Roku reported an impressive quarter, validating our view that it is one of a handful of companies leading the transition to over-the-top video consumption,” said Tom Forte, an analyst at D. A. Davidson who also called the results “outstanding”.

Roku shares were last up 6.7 percent at $38.55 in premarket after having fallen nearly 30 percent this year.