Have you heard of Amazon Local?

Amazon Local is similar to Groupon and Living Social, but they currently house less offers. 

Anyway, right now you can get a free Uber coupon, if you sign up with Amazon Local. I did it yesterday, and today I received a Free $10 credit that's good toward a $10 purchase or more. 

Also, if you're a new user you can sign-up here and receive a free $5.00 credit.