The commercial availability of the Apple Watch has not significantly affected Fitbit's sales, according to a report from Slice Intelligence, which aggregates data from online e-receipts. The company says it collects data from a panel of more than 2.5 million online shoppers.

Although the Apple Watch is a smartwatch and not a dedicated fitness device, like Fitbit's devices, when Apple first unveiled its smartwatch it explained that fitness tracking was one of the Apple Watch's prime use cases.

In January, after Fitbit launched its higher end device, the Fitbit Charge HR, Fitbit saw a resurgence in sales. And while its sales slowed in the months leading up to the Apple Watch launch, Apple's sales have since recovered. Slice explains that this might mean that consumers waited to see the Apple Watch before purchasing a device. 

When the Apple Watch first went on sale, it sold almost 1.4 million watches, according to Slice's e-receipt data, but in May 2015, 850,000 Fitbit devices were sold versus 777,000 Apple Watches. The research firm also found that just 4.8 percent of consumers who bought a Fitbit device also purchased an Apple Watch.

Slice also broke down where consumers were purchasing their Fitbit device. The majority of Fitbit sales online, 43 percent, are coming from Fitbit.com, which might indicate that consumers are specifically seeking out this brand. After Fitbit.com came Amazon with 40 percent of the sales followed by BestBuy, which offered 7 percent of online sales.

Last week,  Fitbit debuted its initial public offering on the New York Stock Exchange after increasing the price of its shares to $20 apiece: The IPO raised $732 million, making it the biggest consumer electronics IPO in history, according to Dealogica. The stock began trading on the NYSE above $30 a share.

Fitbit’s IPO beat out wearable camera company, GoPro’s big $427.2 million IPO from last summer, and even topped the former consumer electronics IPO record holder, Duracell, which pulled in $433 million from its 1991 IPO.