I have a BIG VENT...
Those with particular companies who join forums and message boards and ONLY spam ads. They do not come into the company specific threads and chit chat post...they don't introduce themselves and frankly they don't post anywhere else on the forums except in the ads threads.
I think this is unprofessional in my opinion. I dont have an issue with placing ads, I do it too but I take great issue with those who join forums and just make daily rounds spamming the ads threads.