Wayne, I do lots of things that seem not work, but I'm busy most of the time. I Believe everything has a cumulative effect. These cards might not bring in a great deal of work but they keep me in the customers mind, so 3 months later when they do need something cleaning they remember me.
I don't know if anyone remembers last year I gave out cans of de-icer, last month I got a job from the carpet shop who I gave 4 cans too.......10 months later!! They mentioned 2 cans were still under the counter.
Lots of little things continuously
Derek in some ways I agree.... But when it comes to marketing I always think will it do any harm or impact on my company in a negative way if not then no matter how wacky I'll give it a go