We all know about hate calls or letters as a reaction to mail campaigns, especially to blind offers.
Probably nobody likes receiving those but there are ways of dealing with that (e.g., using an answering service instead of answering the phone by yourself).
Other than those calls / letters, what other negative impact did your mail campaigns have? I have heard for example of a case where recipients of blind offers left negative reviews with the Better Business Bureau. I have heard of another case where a complaint was filed with the state's attorney general (which, from my understanding, didn't lead to anything substantial, but the attorney general still sent a letter to the person who sent out the mail campaign (I think the letter was just informing about the complaint)).
Curious to hear about your experiences.