While the long-term success of the Apple Watch remains to be seen, the new gadget got off to a roaring start, according to a new report from IDC.

In its latest wearable tracking report, the marketing research firm said Apple shipped 3.6 million units of the Apple Watch in the second quarter of 2015. That’s a big number, considering the watch wasn’t on sale for the entire three-month period.

That makes Apple the second largest wearable company, behind Fitbit, which sold 4.4 million units during the same period. Given the higher average cost of the Apple Watch, it’s quite likely that Apple’s revenues from wearables is already bigger than Fitbit’s.

Overall, Apple’s entrance seemed to draw attention and boost sales for the category. According to IDC, the number of wearables shipped in the quarter were 18.1 million units, up from 5.6 million units from the same period a year ago.

“Anytime Apple enters a new market, not only does it draw attention to itself, but to the market as a whole,” said Ramon Llamas, research manager for IDC’s Wearables team, in a press release. “Its participation benefits multiple players and platforms within the wearables ecosystem, and ultimately drives total volumes higher.

The question now is how much of the demand for the Apple Watch was front-loaded.

On one hand, there were reports that sales plunged dramatically after the initial rush to buy among hardcore Apple fans. On the other hand, Best Buy was very enthusiastic, saying the watch had been a big hit, had helped boost the store’s earnings, and that Best Buy was going to expand sales of the watch to all of its stores.

IDC also noted that when it came to wearables that can run third-party apps, Apple was already the leader, shipping two-thirds of all so-called “smart wearables.”

Still, the quarter was far from a catastrophe for Fitbit, indicating that there may be plenty of room for several wearable winners.

According to IDC, Fitbit experienced triple-digit year-over-year global growth in units shipped and new partnerships, and increased its brand awareness.

Xiaomi of China was third in wearable units shipped last quarter, followed by Garmin and then Samsung.