I think it has something to do with number of posts as well. I haven't got many reputation points, good or bad, from other members. My guess is that if you participate, and nobody complains, it must have been a good thing. Personally, don't even care. I just enjoy using the forum, share my thoughts, help where I can. I learn a lot of new things, find new ways to look at a problem, and get inspired for new projects. I get tons of project ideas, but little spare time to get far into them, occasionally share, some are probably better kept to myself.