In creative writing it is well known to "show, don’t tell." In other words, don’t TELL us she is a brilliant scientist, SHOW her doing something brilliant.
The same holds true for startups and entrepreneurs. We all tend to TELL the potential investor or customer what we will do for them. Talk is cheap. Anyone can say anything. SHOW us what you have DONE and it will mean so much more. What is amazing is one entrepreneur can TELL me they will take over the world (let’s assume they do it with a wonderful slide deck, charisma, and are darn believable), but if another entrepreneur comes in and SHOWS me they have taken over Rhode Island… I know who I’ll be more excited about.