I assume you mean just "subscribers' like you said.
I have tried the snail mail post card to previous customers on two occasions. I had professionally printed cards and included a "coupon code". Nadda. Both Times. I have been somewhat hesitant to do email campaigns since I had a customer in the past ask to exclude them in future emails. So, I tread very carefully on the customer email area. However, perhaps I should take another look at the "mailing list" folks that intentionally "opted in" to the email list. One reason I hadn't looked at that is because I NEVER got a notification that someone joined my list!!!!
I had to include a bcc to my email of my site on the auto generated emails for joining the mailing list!
