Online retail giant Amazon is reportedly inviting select customers to participate in a body scanning program as part of its effort to ramp up online clothing sales.

Those who are selected will be required to participate in the scanning program over a twenty-week period, to see how their bodies fluctuate over time, according to an article in The Wall Street Journal.

Amazon will potentially be using a 3D body-scanning unit, which was developed after Amazon bought Body Labs, a software development company that created a technology able to capture a body’s shape and motion in 3D. Body Labs originally created the technology to enhance video game users’ experience while playing, but said on its website that the technology could also be used for fashion, according to Business Insider.

Participants are being directed to a facility in New York, where they will be scanned every two weeks for thirty minutes. They will also receive $250 Amazon gift cards for their participation, according to reports.

There is speculation surrounding Amazon’s adventurous move; that perhaps the technology is being developed so that customers can virtually try on clothes before committing to a purchase. Amazon has not yet commented on the invitation or speculation.

There’s no doubt the online retail giant likes to track information about its customers to market to them effectively, and this would be no exception. Amazon already uses customer searches to advertise other products within the site. The question is: are customers ready to give up details about their bodies in order to shop for clothes more easily online?

Online privacy concerns have been in the news a lot recently, most notably Facebook’s data breach with research firm Cambridge Analytica, where the firm reportedly stole personal data from more than 87 million users. Equifax also experienced an extensive data breach last year, leaving customers vulnerable to hackers and identity theft. Many users are weary of giving up so much information that could be sold to third parties, stolen, or used in inappropriate or unauthorized ways.

In the last year, Amazon has made efforts to grow its online clothing presence, including expanding its private label brands, offering a try-before-you-buy and return service, and setting up physical lockers in town for customers to conveniently retrieve their purchases.

Macy’s is still the biggest online clothing retailer in the U.S., according to the latest industry reports, but Amazon is set to overtake them in the next year to grab the number one spot.