On this site in particular, we do need to attract experts and professionals in industry. Unfortunately, self-promotion is frowned upon.
See this question (and review the edits) : What type of concrete sealer to use to prevent frost heaves in my driveway?
The problem here is that the answer is REALLY GOOD. This is exactly the type of expert we are trying to attract. However, we need to allow some form of promotion to exist here in order to make it worth their time.
I would suggest allowing blatant self-promotion in the profile, and then allowing a "See my profile for my company information." as the only promotional text in the answer body.