Your customers know who you are: after all, they’re your customers! Isn’t your marketing time better spent on targeting new prospects? NO! Studies indicate that it costs you 5-10 times as much to gain a new client as it does to sell to an existing one. Even if your past clients don’t currently need your services, there’s a good chance that their friends and family do. When you stay in touch with past clients, you are not only reaching them, but reaching their entire social circle.