The Sales totals in the Customer Summary Card is normally considered a total of sales made to customers. The actual make-up of this value may include more than just raw sales dollars depending on the Receivables Setup.
In the Receivables Setup Options window (Tools -> Setup -> Sales -> Receivables -> Options in Version 9.0), the Sales History Includes at the bottom of the page defines the amounts that will be accumulated in the Sales totals in the Customer Summary card. Checkboxes include Sales, Discounts, Freight, Miscellaneous, and Tax. Checking each of these boxes will include the indicated amounts in the Sales total on the Customer Summary screen.
