
Google really wants you to share Project Fi with your friends and family, and they're willing to pay you for it. Last year they launched a referral program for the wireless service, but this summer you can take part in a Fi Referral Challenge to win a few prizes for getting other people to sign up on the network.
It's pretty simple and works like any other referral contest. Simply grab your referral link, then share that with people when they sign up. You'll get credit, and Google is doling out rewards based on how many sign-ups you get.

Two referrals nets you $20 in Google Play credit, plus $40 Fi credit. Five referrals bumps the Fi credit to $100, and you get a sweet Fi weekender bag. And for the top three referrers in the contest, they'll get a ton of Fi credit and a trip to Google HQ.
The contest runs until September 25th. Get crackin'.
source: Google