Maybe I've missed it, but what's the incentive to accept a friend trial over just downloading the game and start the free trial right away?
Wouldn't it generate a lot more sales and subscriptions if you just add the speeder to the new account on first subscription payment, as well? Or at least some kind of item exclusive to the referral program?
Right now it's just the same as if you just went straight for the free trial, except for somebody else getting something nice out of the deal and you won't get anything. Sounds like a bad deal to me.
Because your friend is not a douceh and is willing to give a little bit extra effort/patience for you to get the speeder?