Would it be possible to separate those webchats that are clearly vehicles for publicity/promotion from those which have been requested by MNetters? Rather like you have a topic for sponsored discussions?
I'm tired of those webchats where, despite some very interesting questions being asked, the guest will only talk about his/her work that they are promoting.
Or, if this isn't possible, could you please brief people who want to come and talk to us better? i.e. that there are likely to be some challenging/difficult questions put their way, and would they please give some time and consideration to those?