I was eligible for the Neutrogena Rapid Clear All in One Scrub and Daily Lotion. Basically, I just enter my address and they'll have the product shipped to me, with no fee!
Hopefully I'll get this item in the mail soon. I'm not sure what size it is but I'll probably post about it when I receive it.
Klout gives you a little title as well which I found to be quite cute.
Whether or not Klout gives an accurate measure, is questionable. You can read the article about it on Mashable: http://mashable.com/2012/03/23/klout-influence/
At the end of the day, I just want the perk :) There are a few good ones as well that I've seen related to Acura ILX (wish I was influential about cars).
Check it out let me know what you think via comments or Twitter.