Now if we could just get a thanks button...
Trust me. It's a bad idea.
Well that is debatable. Nearly every form of profitable social media has some form of it. I'd be interested in hearing your reasoning against it because in every debate I've seen about it the pros and cons are basically equal and it comes down to personal preference. I don't feel strongly about it either way but I think it's a proven tool to get more contributions, though the quality will always be varied.
This should be its own topic if we want to really discuss it. We had a "rep" system for a while on totse2. It worked for most, but a select few individuals abused it and ruined the experience. The main method of abuse, however, was by repeatedly and unnecessarily negatively repping people, so I'm not sure if there are too many downsides to a positive-only option, such as "thanks." Still a discussion better suited in a separate topic.