To date I have referred one sign-up to adsense that user is active and when they made their first $5 I received $5, I never really thought much of it, but today when checking out my account I noticed an extra $250 dollars, at first I thought it was from an ad click and I was like wtf, took me awhile to figure out it was from the referral making their first $100.
My thoughts are that if your able to refer many people to adsense the bonuses should be pretty much guaranteed, it is the most common way to make money online and most people I think would stick by their accounts and use them.
After receiving that referral bonus I took a closer look at the bonuses and the amount of money you can make from them is pretty crazy.
Here's a run down:
Adsense - When a publisher your referred makes $5 you get $5, when they make $100 you receive $250, if you can get 25 other referrals to do the same as above you will be awarded a $2000 bonus. All of this is with-in a 180 day period.
There's a few other bonuses available for other google products to.
The bonuses seem crazy as, so much money to be made, I just wish I had a few other referrals under me, anyway that $250 made my day and it just adds to what is looking to be a great month of blog earnings for me.