Since contacts can be referenced in financial transactions, you can view a list of sales involving the contact by pressing the search button.
You will also see a revenue history summary with the following fields:
Animal Purchases: is the total head count purchased by this contact.
Total Purchases: is the total number of purchases by this contact.
Last Purchase: is the last time this contact made a purchase.
Average Animal Spend: is the average amount paid per animal.
Average Total Spend: is the average amount paid per transaction.
Total Spend: is the total amount received from this contact.