Smart speakers had a good holiday. Amazon already said its Echo Dot outsold all other items on its site this holiday season, which hinted toward the sizable growth for the voice-powered speaker market. Today, research firm CIRP is reporting the U.S. installed base for speakers grew to 66 million units in December 2018, up from 53 million in the September 2018 quarter and just 37 million in December 2017.

However, holiday sales didn’t have much impact on the market shares for the various speaker brands, the firm found.

Amazon Echo devices still lead the U.S. market with a 70 percent share of the installed base, followed by Google Home at 24 percent, then Apple HomePod at 6 percent, the report said.

“Holiday shoppers helped the smart speaker market take off again,” said Josh Lowitz, partner and co-founder of CIRP, in a statement. “Relative market shares have remained fairly stable, with Amazon Echo, Google Home, and Apple HomePod accounting for consistent shares over the past few quarters. Amazon and Google both have broad model lineups, ranging from basic to high-end, with even more variants from Amazon. Apple, of course, has only its premium-priced HomePod, and likely won’t gain significant share until it offers an entry-level product closer to Echo Dot and Home mini,” Lowitz added.

Also of interest is that some portion of those buying a smart speaker for their home already own one. According to CIRP, 35 percent of smart speaker owners now have multiple devices, as of December 2018. That’s up from 18 percent in December 2017.

This figure is key to the device makers’ larger strategies, because it means that once a company is able to get that first sale, the consumer may return to buy more devices from the same vendor.

Amazon had gained an early advantage here, initially convincing more users to buy another speaker compared with Google Home users. A year ago, almost double the number of Echo users had multiple devices, versus Google Home owners. But Google is catching up, and now about a third of Echo and Google Home users have multiple devices.

It’s worth noting that CIRP data — like much that’s produced by market research firms — isn’t always going to match up exactly with other firms’ estimates and forecasts.

For example, Strategy Analytics this fall said that Amazon’s Echo market share in the U.S. was 63 percent, to Google’s 17 percent and Apple HomePod’s 4 percent. Meanwhile, eMarketer’s 2019 U.S. forecast predicts Amazon Echo will end up with around a 63.3 percent market share this year, versus Google Home’s 31 percent, with all others, like HomePod and Sonos, reaching 12 percent.

That said, the broad strokes across all reports point to the same general findings — that Amazon is leading the U.S. market by a wide margin, and while that margin may be shrinking, it’s not going away soon.