How long do you go before finally saying enough is enough when it comes to chasing down past customers?
For example, a customer in the past had you apply a one time application to control dandelions, but you want him to sign up for more applications this year. How far and how long do you go trying to get him/her signed up for services even if you still hear no response from him/her?
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What type of things have you done so far to chase them down? Would a brief stop at their house help?
I had this drain company that called me once a week for months to get me to resign up for their services when a previous contract ended. Most of the time I just missed their call, but one day they caught me on the phone and I agreed to have them renew it. So maybe that will help too.