Of course you should listen to your customers. But the wrong way to listen to your customers, is just to add features or just to read their emails and take them

Of course you should listen to your customers. But the wrong way to listen to your customers, is just to add features or just to read their emails and take them literally. You have to analyse the reasons behind their requests. Why do they want this feature? What problem are they trying to solve with that? When you are doing usability tests, you don't just listen to the user explaining whats going wrong you are watching him. Often the user explains that there is a problem with your buttons but in reality he just has a problem with some descriptions. What the user thinks and what he does are two different sides of the same coin. You need to find out "What is the problem?" and solve it. The user might say "I need larger buttons on my phone, they are too small" but the problem might be that he makes many mistakes. Now this is a totally different problem and you can solve it in many way (auto correct features, voice recogn,... or something totally new). Now if you find a big problem with big business potential most users will have this problem, but the won't be aware of it. Think about Dyson, everyone had this problem, you have to buy bags for your vacuum cleaner, but this wasn't problem most people were aware of. Now Dyson solved it and instantly everybody was aware of it. Think about phones, they ahd more and more features, but most user were not able to use them. Now Apple solved that, most features of iphone where available before the iphone but suddenly people where aware these features existed and they could use them. Listen to customers, but don't do it "literally" ;-)