I have only been going a few months but find the same issue happens at a high rate. When i quote for a job i always ask if the customer wants a regular service and the frequency. most say yes and agree to the service intervals i advise but once the initial service is done they say we will call you.
Q1 - do you give a slightly better rate in the hope of making it up on a regular basis or just charge the full price as it is generally a jungle?
Q2 - if yours say yes to ongoing do you use a service contract / agreement?
thanks in advance.