First off, Welcome to Fluther! As to the deal between your wife and her friend, it sounds like they had different expectations from the deal. Was there anything put into writing up front? I think if it was my business and I was going to demonstrate this new product and had a friend that was going to help, I would have asked up front for financial assistance from that friend if I expected it. If, as a friend, I offered to be the “model” for the demonstration, I would consider my role just that….a body to be used to show how the machine works. I would not consider up front that it would cost me something. I would view it as something like a fashion designer using a model on a runway. The model is doing a job…showing off the product. Would it be right for the designer to then turn around and tell the model they had to pay for the clothes they wore? I think being friends is the initial problem. They needed to talk more up front.