Someone's bound to ask, so the answer is they credit $35 to your balance within about 2 months of account opening.
Too bad Discover recently watered down their CashBack bonus program. Sure, it was never a lot of money anyway, but every little bit helps.
Edit:
The CashBack bonus tiers pay less than they used to. The difference isn't much, but it's something like $5 less for the first $3000 charged. After that, it's the same (1% of charges). It is an improvement that you can now cash out in $20 increments rather than wait until the 12 month cycle is ended.
I still have and use my Discover card, but *much* less frequently than a couple years back. Another positive for signing up is no-fee 0% B.T. for 6 months, which ain't bad at all!