I posted this earlier in an IGT but I'll leave it here for those that missed it.
"If you go to your settings page you'll see a "rep power" above the posts you've thanked and a "total rep" above the posts you've been thanked in. Each "Thanks" is the equivalent of 1 rep. As you build rep, your rep (or dislike) power grows as well.
I.E. Currently I have 13 rep power. If I was to "thank" a post, the poster would still receive just 1 rep. If I was to positive rep a post, the poster would receive 13 rep. If I was to negative rep a post, the poster would lose 13 rep. Make sense?
The star next to the thanks button is how you use both the rep and the dislike. There is an approve or disapprove selection screen when the star is clicked (approve=rep, disapprove=dislike). You can also leave a comment along with either that will show up as a notification to the user. Keep in mind that you can only give out so much thanks, reps, and negs in a 24 hour period before you are only allowed to thank posts.
Happy disliking!
"