"Customers are the only experts" certainly is an interesting point , don't you think? 

One of the thoughts that I shared with my students and marketing teams over the years is that we need to "lose the ego". That is, we as marketers cannot believe that we have thought of everything, that the customer is totally predictable, that we know for sure the way the market in general will react to our marketing efforts, product launches, promotions, communications. 

In the end, the customer decides. Yet, we can and do definitely effect or influence those decisions....if we are fairly good at what we do. 

Thoughts?