I'm not sure I understand what's the added value of the service offered : unless you have a deep understanding of your customers business, what are you going to chat about on their website with their potential customers ?
The value of what we do seems to be that we're available for the visitor, we do our best to help (fast response, personable, etc.), etc. And if we don't know the answer, we commit to getting them in touch with the right person on your team (i.e. a lead for you, and a happy visitor).
We do have a good onboarding process / workflow to make sure we know enough about the customers business to help visitors (see other HN comments in the thread), but the core value is that we're there, personable, and do our best to help.