Sending a sales follow up email is important because completing a sale is not (or at least should not be) the end of your relationship with your customer. One of the hardest things to do when selling a product or service is acquiring a customer. Once you have that customer it is a great idea to get to know them and continue to offer help and support for the product they just bought from you. If you are running your online business with WordPress, Cart66 provides the tools you need to stay connected with your customers.
https://www.youtube.com/watch?v=Q2XDr5AQZQI