It's fine when you have ~50 customers, but when you're talking 3, 4, and 5 figures, then it's an impossible model to sustain, and will actually make the company look worse (imagine 50 people, all with a small issue. 50 x 5 minutes = too long a wait for customer #50).
That is why you have more than one person on the live chat system.
If you have say ten people, then the maximum one needs to wait if a chat session takes five minutes is twenty five minutes. But if you have so many clients, you're going to have more than ten support people [Or at least should do].
My company however no longer offers live chat support. The reason being that people did not use it; and it became too expensive for its use. You have to pay someone to be on line, and when no one is using that support system, it's money going to waste.
Occasionally a client would contact live support, however no often. Pre-clients did not even contact live support that often. The reason being that they all found it much easier to simply submit a ticket or send an e-mail.
Submitting a ticket is very easy, and very quick - It does not take much; and at times can be quicker than live chat.
If you have a demand, then supply, however if there is no demand it is silly to supply.
I may re-introduce live chat support, however it is very unlikely. Having support handled by a ticket system makes it a lot easier for everyone - the clients, the staff and me.
Also, what you should do is go over the support chat logs if you hire someone else to respond so you know that they're doing their job. I found it easier to go over tickets then to go over chat logs; however that is just me.
Also another hassle was that live chat support was offered also via AIM, MSN, ICQ and YIM. Making it more difficult to check up on the support logs.