Returns are a constant. They are an insignificant percentage of sales. At first I was worried but after reading on forums from other publishers who shared their return rates, I didn't worry about it. Shopping in the U.S. is all about returns.

People try it and then return it. They may even keep a copy.
I encourage people to email me with all questions and concerns. Most often, people do not know how to use DVJ or some other issue that is fixed by education (for example, the usual Ps 119 is numbered as Ps 118 in some translations that follow the Septuagint Psalm numbering; people accused me that their Ps 119 is missing verses!). There were a few instances when there was an oversight on my part but I have always addressed those almost immediately and posted here.