As the percentage of U.S. households that own streaming media players climbed to nearly 40 percent at the beginning of 2018, Roku managed to maintain its lead in market share while Amazon is gaining ground, according to new research from Parks Associates.

The firm found that Roku’s share of streaming media players owned in U.S. households has remained strong at 37 percent for the last year. Amazon, meanwhile, saw its share rise 4 percent to 28 percent as the company took some of Google’s portion, which has been declining since 2015. Google’s Chromecast share now stands at 14 percent, falling 4 percent and for the first time behind Apple TV, which held steady at a 15 percent share.

Eight years ago, only 6 percent of U.S. households owned streaming devices, according to Parks Associates.

"Since their inception about a decade ago, consumers have purchased streaming media players due to their modern and friendly user-interfaces, wide app support, and low cost, making them easier to upgrade and replace than a television set," said Kristen Hanich, research analyst at Parks Associates, in a news release.

Parks Associates: Streaming Media Player: Brand Share by Installed Base

Hanich said that when ranked by consumers, Roku devices lead in multiple usability categories, while Amazon’s Fire TV has moved up to second place in the ease-of-setup category. She noted that Amazon is catching up to Apple TV in a number of categories, including ease of finding something to watch, “which could account in part for its growing market share.”

Apple TV ranked first when it comes to gaming and the ability to purchase content.

Smart TVs, unsurprisingly, are also rising in popularity, with adoption in more than 50 percent of U.S. households.

“Ease-of-use is the most important factor to consumers when it comes to choosing which entertainment device to use, and these two devices [streaming players and smart TVs] are competing directly in terms of usage, while usage of gaming consoles for video has declined,” the firm noted.

Though the proliferation of smart TVs is greater than streaming devices, the latter appear to be getting more use. Parks Associates found that more than 70 percent of streaming media player owners use their device at least once a week, compared to 59 percent of smart TV owners. Additionally, 37 percent of smart TV owners report daily use, while streaming device owners are at 44 percent.

"Smart TVs earned the highest Net Promoter Score (NPS) among consumers out of all the CE products Parks Associates tested, but streaming media players still have higher usage rates, indicating these devices have firmly established their role in their ability to connect users with content quickly and easily," Hanich said.