Each time you make a sale of your product or service, you should send a follow up e-mail to that person. After all of your effort in earning their trust, they have decided to spend their hard earned money with you. The least you can do is let them know that you appreciate it -- AND PEOPLE CONTINUE TO DO BUSINESS WHERE THEY FEEL APPRECIATED.
Building Relationships
To be a successful business person, you know that your true success lies in building the type of relationship with a new client that result in sales of your other products or services to them. Unless you set up a series of messages in the right way, however, they will just unsubscribe from your autoresponder and you will have squandered your opportunity.
First rule: Don't try to sell them anything else immediately. After all, they haven't even had time to use the initial product yet. Remember that the process is all about building a relationship with your client so that they will listen to you in the future. You need to be creating value for your client, so that they will trust you when you tell them something.
For example, most people that are trying to build a business usually end up buying quite a few e-books. I know I have looked at dozens of them trying to learn what I need to be successful marketing online. I continue to study everyday simply to keep up with the fast pace of change on the Internet. Do I have the time to read everything cover to cover? No, but I scan them all to see if I can quickly find new that will help me. Then I forget I even have some of them until the day I go through cleaning out my computer.
If someone started following up with me and teaching me how to utilize their e-book by reminding me of the different things in various chapters, the chances are that I will open that book back up again and check it out again. That's what you want to do. If your product is a book, you are trying to get them to open up the book again and read it some more. The more they read it, the more value they get out of the book. The more value they perceive your product has the more they trust you. The more they trust you, the greater chance they will do business with you again.
If you sell a software product, then teach them how to use the software product. If they feel the software is too complicated to use, they will put it aside and not use it. If they don't use it, chances are they will be skeptical of buying anymore software from you. If they learn to use it a lot, it is a good bet that they will want to upgrade the next time a new version comes out.
If you are selling them a service, teach them how to use all of the features. The more features they use, the greater value they will believe they are getting for their money. There is nothing more efficient creating this value and trust than using an autoresponder to educate them about your product or service. BUT, if you start trying to sell them additional items before you have created that level of trust -- you may be viewed as just another fast talking salesman and lose them instead.