Christine,
I'm not familiar enough with Anscers to address any other site or their members. It is interesting that you mention Michael, whose cogent comments have been missing of late. I don't know if that is because he is not part of our site, as you mention, or for another reason. Could he be an example of the cycle to which I referred? I hope not.
But, I was not so much offering suggestions in attracting seasoned professionals to our site who are not already here as I was making the case that we need to recognize those already on our site who contribute now as well as proposing that CMA devise methods to encourage others on our site to contribute. And in both cases, CMA could design a program to keep the old and the new contributors active for the long-term. Whether this is accomplished by Reputation points, Activity Level points, special titles like Mentor, etc., or tangible awards are all possibilities that should all be on the table.
All of this only makes sense if you agree with my premises. 1. The Community has been up for some time in one fashion or another. But over this time I have not seen any marked increase in the number of distinct responders. 2. The number of repeat contributors (generally speaking) is a small group. 3. It is natural that for controllable or uncontrollable reasons their responses diminish over time. 4. It is appropriate to recognize them in some fashion. 5. It is prudent to entice others to contribute.
I have no solution for attracting more professionals to the site or in increasing the participation of those already on the site. I'm only attempting to bring it to CMA's attention that it might be a worthwhile project to build and improve positive momentum.