Last night, Google released a teaser for the Pixel 4 which confirmed that the upcoming Google flagship will feature Face Unlock and, as rumours have been suggesting for some time now, Project Soli for motion gestures.

Now, in reports from Android Police, and ZDNet, confirmed by Google to The Verge, it seems the company asked random strangers to let Google employees take their pictures in exchange for $5 gift cards from Amazon and Starbucks.

The company said that the ‘field research’ was carried out to gather additional face-scanning data and ensure its face recognition and unlocking technology was accurate. After all, the company’s face unlock system will be compared with that of the 2019 iPhone.

Speaking to The Verge via email, a Google spokesperson said “Our goal is to build the feature with robust security and performance. We’re also building it with inclusiveness in mind, so as many people as possible can benefit.”

The company got the people it collected selfies from, to sign a consent letter that allowed the Mountain‌ View giant to keep their selfies for up to 5 years, however, it will only be keeping them for 18 months for research purposes, the company told The Verge.

The company said that along with the face scan, it is collecting infrared, colour, and depth data, and in an image the company shared of its face-detection set-up, we can see that it’s using a dot projector and IR‌ scanner, so clearly, Google will be using 3D scans, similar to Face ID on the iPhone, and thanks to the IR‌ scanner, it’ll work in the dark too.

Google has claimed that its face unlock technology will be secure enough to be used for payments and for logging in to apps, and has also stated that a user’s face scans will never leave the device — that makes it very important for the company to get facial recognition right, and collecting real-world data from people by giving them $5 in gift cards is just how Google decided to approach this problem.