I was a little unclear on whether you meant just embedding chat into your clients' websites, or running separate instances of SmarterTrack. To play it safe, I have provided answers for both.

If you are just trying to embed chat in each separate instance, this can be handled with just a single install of SmarterTrack. Keep in mind, this solution would store all of the chat information in the same database.

If you are trying to set up separate instances of SmarterTrack, then you must have multiple installs. Each SmarterTrack instance must be run from a separate installation. There is no mechanism in SmarterTrack to allow switching data sources based on the host header.