It'll be just too easy to open a long thread and click 'Thank' on every posting.

You can of course try to introduce some metrics to restrict, this, e.g. that you can't thank someone else until such-and-such etc. But that has been tried before, elsewhere: Brighthand used to have a complex 'reputation' system, where you at all times had a certain amount of 'reputation points' that you could handle out to someone. This resource could increase and wax after certain rules.

It was very difficult to artificially increase someone's reputation, and you could only hand out a certain amount at any time. In many ways a person's reputation on Brighthand seemed to be a more accurate 'karma' measure (a kind of Thanks+Karma integrated into one) than our system here (except that our Karma also takes into account more than Thanks), but in the end it was disbanded anyway. It was explained why here: http://forum.brighthand.com/showpost...55&postcount=1