Lots of integration with other channels
If a visitor does not provide his contact at the beginning you can not add them afterwards.
It is a solid product but one thing (quite silly in my opinion) makes it quite useless in our case.
If a visitor does not provide his details the at the beginning (they call it pre-chat survey) you can not add those details (email,name) afterwards.
You can have a 2 hours chat session with a visitor but visitor will stay as unknown since you can not add the information you gathered during the chat session. How st..id is that?