We send out some mass mailings to self-storage businesses with a large number of facilities. It hasn't been a problem yet but we are sending out a fairly good size coupon which we lose money on in the hopes of encouraging first time customers and we did a bit of 'what if' math. Several of these have 1000 to 2800 facilities nationwide. I was thinking it would be great if there was a secondary dimension built in for restricting the coupon use ie One use per email AND [business group or availability group or price group or @emaildomain.com]