Intercom has a very confusing billing structure. Most products are sold by seat. They offer 'Messages' which is essentially a chat function & 'Inbox' which is a direct-messaging solution.
We moved from Olark to Intercom. In my opinion, Intercom is an expensive solution that is sold very well by experienced and well-trained salespeople.
If you are a smaller sized SMB then I would recommend trying a different provider. Our monthly spend with Intercom is $1162 per month for 8 seats.