I've been less than impressed with the not-so-special offers lately too. Fortunately, I was able to take advantage of the $100 gift certificate when I opened an Amazon Rewards account. That alone almost paid for the KSO. Even though I don't like to open new credit card accounts, I made an exception for that offer.
Hopefully Amazon monitors the response to the special offers, as presumably the book-related offers get the most responses, and will focus on that type of special offer. Otherwise, it's not really a special offer - it's just advertising.