Roku continues to lead the U.S. among OTT device makers in terms of penetration into U.S. homes, owning 37% of the market, according to the latest Parks Associates figures.

That market share is flat with a tally conducted by press a year ago.

The research company’s latest report said that OTT devices are now in 40% of U.S. broadband homes, up from juste 6% in 2010.

Amazon’s share of the OTT device market experienced the largest growth, expanding by 4%.

The news of is of interest to linear pay TV operators, who are trying to shift customer streaming habits to their proprietary leased set-tops—or, in some cases, port their service offerings to subscribers as apps running on OTT devices.

“In terms of usability, consumers score Roku, Apple TV, and Amazon’s Fire TV highly,” said Parks research analyst Kristen Hanich. “When ranking these devices, Roku leads in multiple usability categories, while the Apple TV leads in terms of gaming and the ability to purchase content. Amazon’s Fire TV has moved up to second place in the ease-of-setup category and is close to the Apple TV’s score in several more, including ease of finding something to watch and ease of purchasing content, which could account in part for its growing market share.”

The Parks survey found that 70% of streaming media player owners use their device at least once a week, with 44% reporting daily usage.

Almost 50% of smart TV owners also own a streaming media player.

For its part, Roku recently disclosed that it's making more money these days from licensing its platform to other device makers, such as manufacturers of smart TVs, than it is selling streaming media players.

Roku reported $75 million in platform revenues in the first quarter, up 106% year over year. While the growth is impressive, another contributing factor to Roku’s shifting balance sheet is declining device revenue. For the quarter, Roku totaled up $61.5 million in device revenue, down 3% year over year.