Every year in early Fall, I send out fliers to previous mouse customers advertising the annual mouse treatment. These fliers contain a postcard that the customer can drop in the mail and when I get them back, I call and set up an appointment. It works great for me and the customer. They don't have to remember to call from year to year, because they get a reminder from me. The only "problem" is that as my business grows, the pile of postcards gets bigger and bigger every year. It's one of those "problems" that's nice to have. Right now, I have two piles. People I've called, and left a message, and people I haven't gotten around to calling yet. Once I talk to them, and set up an appointment, the card goes in the waste basket. The ones I've done so far has shown that last winter was a very good year for mice (lots of them around). I use poison bait, and the bait that is remaining this year is a lot less than usual, meaning there were a lot of mice last winter.
