Dollar Tree Friends and Family event

Was in DT today and they were handing out a coupon for Sunday July 19 for a Friends and Family Event - 10% off your purchase of $10 or more. It says in little teeny tiny print - voucher must be present at time of purchase and limit of one voucher person. Just checked the voucher is on line
http://www.dollartree.com/custserv/custserv.jsp?pageName=CustomerAppreciation