As per the Uber ride promotions, when a new User registers it automatically gives him 3 free rides and the person who reffered him also get the 3 free rides.
I think the OP will give you his refferal link to signup on Uber, therefore he will get 3 free rides from each of us.
![Grin](https://bitcointalk.org/Smileys/default/grin.gif)
Yes, any new customer will be able to enjoy rides with uber and I guess this is available world wide, where ever uber offers services.
Will you be able to provide free rides even for the existing customers of Uber or only for the new customers who will be freshly installing app and registering ?
If you want free rides beyond new customer promotions ? then you just need another new mobile number or you need to have your friends registering using your referral links. Enjoy many free rides with uber !