If you are using the Quickbooks Synch tool, that also has log data that can be purged.

 

If you are using BTO, there is a database cleanup tool under the help menu that removes expired data.

 

You should identify what version code and what features you are running in order to further define what options may be available to clean up your database.

 

Beyond those, I would really like to see PC feature a selective purge tool that would allow the merchant to remove order data that is earlier than some specific date so as to clear out tables such as "productsordered" and whatever else chews up space.  The idea would be to ascertain the date beyone which order data is no longer important and nuke it, thus regaining space in the database.

 

With that said, one thing you will want to ask your host is if the DB is set for simple logging, and not full logging.  That alone would make a difference, but its probably already set for simple.  Worth checking though.