# Who goes on your customer list, and why old names stay [Home](https://theonlyaxelj.com/en) › [Study](https://theonlyaxelj.com/en/study) › [Articles](https://theonlyaxelj.com/en/study/articles) author: [Axel Jedlitschka](https://theonlyaxelj.com/en/about) published: 2026-10-13 updated: 2026-10-13 language: en reading time: 5 min topic: Marketing & sales source booklet: [Why the Campaign Failed](https://theonlyaxelj.com/en/shop/introduction/marketing-promotion) Your customer list is a list of buyers. Someone who bought once stays on it for years, because the age of a file tells you nothing about the person. Your customer list is a list of people who bought from you. Someone who only enquired does not belong on it, and someone who bought does not leave it just because time has passed. Most self-employed people handle both the other way round. They collect every address that comes past, and every so often they clear the old customers off the list. Both habits look like good housekeeping, and both cost money. ## Who goes on the list The source states the rule firmly: a list of names of people who have bought nothing from the organization does not go into the customer files. It also describes the order of events. A person receives information, and if interested orders something, and only then does the name appear on the list as a matter of course. The logic is simple. Someone who has bought from you once has proved something that an enquirer has not. An enquirer may have left details at a prize draw, or asked a single question. A buyer went all the way to an order, so a message to a buyer reaches someone who already knows you. Suppose a business with 800 email addresses collected through a prize draw and 60 real customers. Writing to the 800 brings in less than writing to the 60. If you want to keep the enquirers too, keep them apart. Take a physiotherapy clinic with two lists, one of clients who booked and one of people who only asked. It writes something different to each. ## Who never comes off This rule saves the most money. According to the source, time has no relationship to what is kept in the files. A customer from last year is still a customer, and the age of a file is no reason to remove it. The test the source gives for an active name is a single question: “do they ever answer?” It also puts a number on it. Getting a record costs at least $10, and a record that is written to continually is worth hundreds. One that is five years old, and has been written to dozens of times, “can suddenly come alive”. Suppose a clinic that deleted the clients who had not come in for two years. Three of them came back later through a recommendation, and by then they were missing from the list when the next offer went out. Set against that a landscape gardener who kept every name and wrote to everyone twice a year. Two customers from four years earlier returned with large projects. Clearing out the list feels orderly, yet in most cases you are throwing away an asset you have already paid for. The booklet defines one exception. Even there, a customer who has bought stays on the list for good. ## Two things that destroy a list The source names two things that destroy a list, and both pass for efficiency. The first is not using the list. The source tells of a list nobody used that dwindled from 40,000 names to 13,000. The mechanism in that story is long gone, but the effect is the same today: email addresses change, phone numbers change, and people forget who you are. A list that nobody writes to decays. Suppose a business owner who left his list untouched for two years. When he finally wrote, a third of the addresses bounced. Or a consultant who sends a brief update every quarter, with news or without. Her list has stayed valid for ten years. The second destroyer is cutting the list down to the customers who look warm. The next chapter of the booklet shows what that cost one organization, in numbers. ## Why the list is worth money Everyone on your list cost you something to reach. That price is already paid, and the only open question is whether you keep drawing value from it. A list of buyers that you write to regularly is an asset that is worth more the more you write to it. A list that you cut down or forget is money you paid and left on the table. This is why the two rules belong together. The rule on who goes on keeps the list made of buyers, and the rule on who stays keeps it from losing them. The two destroyers hit exactly there: neglect lets the list decay, and cutting it down removes people on purpose. The booklet gives this chapter two exercises, one to test your list and one to act on it, followed by a self-check. The booklet as a whole covers the five basics that successful promotion rests on, and building the list is one of them. Before you delete someone you have not heard from in a long time, remember that you already paid for that name to be there. - [Why the Campaign Failed](https://theonlyaxelj.com/en/shop/introduction/marketing-promotion): A diagnosis of which of the five basics is broken in your business, and what to do about it, so you can stop improving the ad for the fifth time. --- [עברית](https://theonlyaxelj.com/he/study/articles/your-customer-list-is-a-buyer-list) · [Español](https://theonlyaxelj.com/es/study/articles/your-customer-list-is-a-buyer-list)