I don't really see how comments helps to sell other than bringing the ad back up . If people used the feedback system that may help . Just think if CL allowed replies to ads posted. As long as you manage your ad and PM's in a timely fashion it should hurt sales a bit.These are ads not blogs.
Oh lord, given the caliber of emails I get from CL listings, there's no way I could imagine a CL like "chat board".
In the past members simply misused the classifieds.
We warned everyone repeatedly with no result.
The loss of ability to reply directly resulted from that.
If "business" is lower, I do not think you can clearly show that it is due to the way our classifieds are now.
If your doing "business" as FT mentioned, you should be a vendor(as per the rules).
I would say it'd be best to actively seek sales by staying on top of your ads, or simply being creative in your advertisement. I see that some people have only a few adds, and only half of them have recent updates to them. Going back to advertising in the classifieds. I know I advertised in the local paper and on CL frequently in my business. If it gets a sale, it gets one. But sealing the deal has always came down to me chasing the sale, not expecting more sales from chatter. I've tried advertising on facebook as well, that never results in sales for me. Just someone else that pipes in with a "So and so has it for X dollars less".