Providers running ads that say "discounts for reviews" will not be permitted. However, stating something along the lines of "reviewer specials" is allowed.
I know it seems like it apples and oranges, but it is all in the wording. If providers want to give reviewers discounts, that's fine. Just don't advertise it that way.

BTW, I am running a special this week myself. Inquire within

I wouldn't want to be around someone who is known for towing the sun around.  That would be entirely too toasty for my tastes!

Is "Specials for reviewers" ok?
If no, then why is "Reviewer specials" ok?
If yes, then why is "Discounts for reviewers" not ok?

I think the distinction is that "reviewer specials" could mean that the special is for those who write reviews with the hope that the client will write a review in this case.  Yes, it does seem like a very line.