Microsoft pays you to use Bing instead of Google.
Once you sign up for Microsoft Rewards, you earn three points per Bing search. In the US, you can earn up to 270 points per day with 90 searches spread across desktop and mobile. That translates to 8,100 points if you reach the daily search limit for an entire month, which is worth around $10.
You can also complete a daily search set for an extra 40 points per day. Do that ten days in a row and you get 150 bonus points. Between these two, you can make an additional 1,600 points per month.
Long story short, you can earn enough points in the US to redeem gift cards worth between $10 and $20 every month. You get more value out of your points if you exchange them for Microsoft services and gift cards. Some dedicated users have even collected hundreds of thousands of points over several months to redeem an entire Xbox Series S. Other redemption options include retail gift cards, charity donations, and sweepstakes entries.