I am in the situation of having a product that doesn't sell. It may very well be that my product is no good and would not sell under any circumstances. However, I have observed the following behavior on the part of some potential buyers:<p>1) When I have barely explained what problem my product solves, people interrupt me with, "But I already have <crappy thing>." After that, they refuse to even consider the possibility that my solution may be better. It is almost comical how oftentimes, I am unable to finish a single sentence for the rest of the conversation. Everything I start saying gets interrupted with claims that <crappy thing> has all these awesome features, which I know it does not. That would be Principle 3, "The Endowment Effect."<p>2) People scan everything that I say for a potential loss or cost that my product may incur (and yes, there is a cost). After that, again, the conversation becomes almost comical, reminiscent of a Monty Python sketch: every sentence that I start will be interrupted with some remark on how devastating the cost would be. It is impossible for me to direct the other person's attention to any gains that they would get. That would be Principle 1, "Losses Loom Larger than Gains."