This is actually a difficult issue. There are many factors to consider. First of all, let it be understood that it is possible for a doctor to be too busy to post on the web. Doctors can and are involved in many things outside of the surgery room, like research, focus groups, writing for medical journals and God forbid - a social life.
Over the several years that I have been involved in this forum it has been blatantly obvious that some doctors have seen it as a powerful and relatively cheap marketing tool. No doubt it is. The problem arises when the forum becomes dominated by the marketeers. Let's face it. When that happens, it loses some of the pureness of being a patient driven forum.
Some doctors have come to this forum to add educational value. That is much appreciated. I love to see the doctors discuss technical issues. Others just post pictures in an obvious attempt to drum up more business. Let me give you an example. I consulted with several doctors before my transplant. About a year after my procedure one of the doctors called me asking if I was ready to do it. That doctor had very little presence at the time on this forum. Soon afterwards I was seeing numerous postings of results from the doctor. Hmmm... I have to ask myself - was business down a little for this doctor? BTW - business seems to be way up for this doctor now, so yes, it is a great marketing tool.
Also, there is so much childish banter on this forum, most doctors just don't want to get involved in that kind of nonsense.
So, what to do? You either, join the club, hire a promotional consultant or do it yourself and reap the benefits. Or you simply remain in the background quietly and consistently doing quality work. I think some doctors feel that self-promotion and/or hiring a promotional consultant is akin to selling out to the dark side. It has a kind of used car salesman type of feeling associated with it.
It is a bit of a dilemma isn't it?