I have ST on my server as well, so I'm able to confirm that SmarterTrack uses a MSSQL database, so that may be on the same SQL server as your store database.  There's likely no way you will get your hands on the source for SmarterTrack itself, so any integration you create is going to be a matter of examining their database structure and building a tool to exchange customer data between the store and ST.

 

I see there is a st_Users table, and perhaps you can write something that sends data from the store  over to that table, but there are several other tables that are prefixed "st_Usersxxx" and I'm not sure what those may be used for, or the extent that those tables need to be included within this integration.

 

To be certain you will need a skilled coder who will be able to evaluate both the ST User and PC Customer table structures, and build a tool that exchanges new and edited data between them.

 

 

You're not going to be able to use a web service for this as ProductCart is classic ASP.

 

However, Greg's definitely suggesting the right direction if what you are looking for is to have the login info be the same in both ProductCart and SmartTrack (assuming that your customers would understand that they'd use their email address as the UID for SmarterTrack). The tricky thing, though, would be how to handle the encrypted PWD in SmarterTrack.