"Get folks' email addresses. Send them stuff they'll like." Let me add to that. Find any reason you can to reply to both customers and non-customers (we happe

"Get folks' email addresses. Send them stuff they'll like." Let me add to that. Find any reason you can to reply to both customers and non-customers (we happen to get misdirected inquires all the time. We try to convert these inquires that we take the time to answer with a coupon and a "use us next time" blurb). Anyway, for customers, this "legit" spam if you want to call it that takes the form of helpful, personal, genuine "follow up" emails (pre-written in a conversational tone in advance and with things that make them look as if they are unique (we use quicktext on thunderbird but there are other ways to do this obviously)) which could say something like "we made that address change that you requested let me know if you need anything further" (more involved but basically just a nice note). So see the idea is not to always have everything to be "self service". If you can afford the labor hit, or the labor hit leads to actual sales maybe encourage customer co-dependency because it gets them to contact you. Of course this is going to totally depend on the business you are in and of course you don't want to annoy customers by doing it to much. The bottom line is "always be selling". Use any interaction by email as a chance to either enhance the customer relationship or make a suggestion for something else they might need.