Make a commitment to be always there for your customers, no matter what. This convinces your customer more than anything to purchase from you.
Customers who purchase from you want to be assured that you will be around for them always. You need to show them your commitment. Nobody likes to make a purchase and then not have any contact with the seller. It could work for something you sell for a dollar or so but for most purchases customers like to know that the seller remains involved long after the sale.
There is surely a reason for this. Your customers want to be sure that in case something goes wrong with the product, you are around to take care of it. Only the actual seller can take care of it. Now you know why there are money back guarantees on almost everything out there today. Check out any sales page online and you will always find one. Mostly, these guarantees are for an extended period of 90 days. This is the time period within which the customer can purchase the product, utilize it and see if it works for them.
There must be a sound money back guarantee as well. The time period should be sufficient for the customer to try out the product to see if it works for them.
In all likelihood, they will not avail of the guarantee. People already choose wisely when they purchase and if all information on your sales page is quite clear, they will have set expectations. If you are honest on your sales page, you will never face the issue of returned products.
More than the money back guarantee, what people are really looking for here is an assurance that you will be around, that you are committed. Most of your customers are not technically minded and if any kind of technical know-how is required with the product, you must be there for guidance. You need to purchase your unlimited support even after the purchase is made.
Be honest about such promises and deliver on them to ensure long term business and regular satisfyed clients.