PunchTab

Similar to Kiip, PunchTab gives you some javascript to put on your site and you can set achievements for your users to do to get points, and then redeem those posts for items or rewards from PunchTab's own catalog like Starbucks or Amazon giftcards, etc. which are handled by PunchTab for you. You can reward them when they visit your website, share content on Facebook/Twitter, etc. I've been using the free service on one of my sites, and the users love it.

Another similar service, hunted by @byosko - PerkHub.com - Haven't tried them yet.

The description also first reminded me of Kiip but this appears to be more on a long-term, CRM-like engagement platform. cc @kunaalarya from Kiip.

Yeah - definitely long-term. We haven't competed with them as of yet. Definitely interesting though. We should be working with them!