I just finished working with a client who owns a small fireworks tent business. He is basically in business two weeks a year and some planning the rest of the year.
One of the things he does is ask people to sign his mailing list. In the town he is set up in that is a daunting task. People are very private and don't want to get on a list. He typically gets about 10 to 15 people per year to sign up. Each year he adds to his list and sends out a letter a few weeks before he sets up his tent. In his letter, he lets his customers know when he will be set up and makes a limited time offer. This year he sent out 22 letters. Of the 22 letters 2 were returned because of bad addresses. Of the 20 remaining, 11 were returned. That is an amazing statistic. What is more amazing is how excited the people where that he was coming back and how they looked forward to coming to his tent. They all made substantial purchases and felt welcomed.
The main comment my client heard was how nice it was that he personalized the letters. The key was the letter was short and sweet, one paragraph long. Then he hand wrote a note to each one, mentioning something he noticed about them. They knew he paid attention to them. One simple letter that probably took him an hour to write, generated lots of good will and revenue.