Apple shipped 600,000 HomePods in the first quarter of 2018, according to a new sales estimates from market research firm Strategy Analytics. With those sales, the firm says Apple should have around a 6 percent share of the market, which puts it far behind Amazon and Google and just below Chinese e-commerce giant Alibaba. According to the estimates, Amazon captured 43.6 percent of the smart speaker market with 4 million unit sales, while Google had 26.5 percent with 2.4 million sales.

There are a few grains of salt here. The HomePod didn’t go on sale until February 9th, so Apple didn’t have the full quarter, which ended on March 31st, to rack up sales. These are also just estimates, as Apple has not released full figures and we don’t know for sure how accurate Strategy Analytics is in this case, though the firm has long monitored tech industry sales trends and market leadership.

And Strategy Analytics is careful to say “shipped” and not “sold” here. While the HomePod may primarily be sold through Apple’s website, where the distinction between those terms may not be as meaningful as it is for other brands, it’s still an important one to point out here in the event a sizable amount of HomePods are just sitting in inventory rooms. Lastly, each of these smart speakers are available in a different number of markets around the world, which affects sales.

Still, the HomePod’s slow start would seem to jibe with news that the product failed to meet Apple’s expectations. Bloomberg reported last month that Apple lowered its sales forecasts for the HomePod and slashed orders with supplier Inventec. Initially, the company saw its smart speaker 10 percent of the market compared to Amazon’s 73 percent, mostly on the strength of an initial HomePod preorder wave, Bloomberg reported, based on data from Slice Intelligence. (Slice’s data appears to differ from Strategy Analytics’ when it comes to how much of the market each company owns.) But that enthusiasm faded after many of the early adopters got their hands on the product, and the HomePod captured only 4 percent of the market three weeks after launch, the report stated.

There are a few reasons why the HomePod may not be selling as well as Apple hoped. For one, the speaker is mostly treated as an iOS ecosystem accessory, like the AirPods, that works best only for those deep within Apple’s walled garden. For instance, the speaker and its Siri capabilities only play nice with Apple Music, and other music streaming services must rely on AirPlay to beam music from an iOS device to the speaker itself and cannot access voice control. On top of that, you need at least one iOS or Mac device to use the HomePod at all, leaving out PC and Android users who may not own an Apple-made device. Apple also launched the HomePod without stereo pairing support, which is coming later this year. Another issue is price — at $349, it’s much more expensive than Amazon, Google, or Sonos offerings. That could be another reason why its market share is understandably lower than competitors’.

There are rumors Apple could develop a cheaper, smaller HomePod to compete more directly with the standard Amazon Echo and Google Home, although more reputable Apple analysts like Ming-Chi Kuo from KGI are not confident that will happen any time soon. Kuo estimated last month that Apple would sell between 2 and 2.5 million HomePods in 2018, which would make Apple’s smart speaker nearly a $1 billion business and certainly nothing to scoff at.