I agree with what Jeff states. Also you must follow up on a regular basis with a mystery shop, use 3 of the majors, a hotmail, Google and yahoo email address and include these in the mail out. This way you know what is going on. You need to have email addresses anyway to Mystery Shop your competitors...Don’t you?? I also always place the name and phone number in the subject line. The majors like this as most spammers do not know the correct name and number combination of the client. Plus as Jeff points out use the CRM tool for communicating important client/ store information, product updates, newsletters, soft sell news releases, community projects etc. There is an old, wise Chinese saying "don’t cook your food in the bathroom" Use an email campaign program for your hard sell if you need to hard sell.
I do not know many consumers swayed by the $500.00 coupon these days, you may find a few. Most Internet shoppers avoid this "gimmick" and are more intelligent. I know BZ Results thinks the sun rises and sets on the program which is an indication of where their thoughts are.
Umer, these are great sources.