I certainly enjoy the convenience of free money! I've only had my KSO a few days so haven't seen many offers, but I did jump on the $100 gift card for opening an Amazon Rewards account. With this one offer, my KSO nearly paid for itself immediately. I look forward to other special offers in the future, although I doubt they'll be as valuable as that single offer was.
Either way, it's a great deal if you don't mind screensaver ads instead of screensaver author photos.