Yesterday, a friend of mine showed me an email that had been forwarded to him by a rep. It had originated with a producer at a major New York agency. That producer had the gall and poor judgment to send out to all the director reps he knew an email that was incredibly insulting and disrespectful. So insulting and disrespectful, that it was forwarded to half the industry, including the producer's boss. The producer has since been fired, and as his email is still circulating, may have trouble finding a job anytime soon.
Advertising is an industry full of big egos. It can be highly political, highly stressful and very competitive. These forces can sometimes turn people into real jerks. But remember this: advertising is a very small industry. The reputation you make for yourself may not be easily shed. And while there are the jerks, advertising also has a lot of very kind, decent people in it. Given the choice between hiring a talented nice person and a talented jerk, I know who I'd go for.