Opt-in list building is a vital part of any internet marketing business. You will often hear marketers quote the axiom: “The Money is in the List”. Your opt-in lists, your customer database, will be made up of people who have either subscribed or have previously purchased from you. These targeted email lists should be cultivated with great care by sending out on a regular basis newsletters, articles, free offers, etc. to keep them happy and to keep reminding them that you are still there. If you do this well they will look forward to receiving emails from you and will look favourably on any new promotions you send their way.