In Dr. Simon Lecture we learn 4 things that a product manager need to have which are:

-Understand factors that affect the product sales
-Compare competitive products and services
-Stay informed about industry and market data
-Create a story behind the product line

so my question is who ever had experience would you please tell me which one is the most critical to the role of a project manager, or you think there is others roles that a project manager would have? your input would be great.