So make sure you keep a list of all your customers. Compile this list in a database of some sort and guard it with your life. Lists are often-times considered the most valuable assets a business can have.
Then send out follow-up/thank-you info to keep the number of refunds down. You can also use this database to send out more offers to your group of clients. Just be sure you send out offers for items related to the product they already purchased.
Like I just mentioned, many successful businesses create new products just to sell to their current customers. This is a smart strategy — they already trust you so they are much more likely to buy from you again.
Another idea is instead of making your current customers purchase your newly developed product at full-price, you could give it to at least a few of them for free or at a significant discount. This works especially well if you are providing ebooks, online courses or downloadable software since these have no overhead cost.
By providing a free or steeply discounted copy of your latest and newest product, your customers will love you for it, you can easily get testimonials endorsing your hot new product before you release it for sale, and you can even use these special customers to test your new product out for you. They can provide you with some solid feedback before you send out an advertisement to new prospects.