Wide receivers are taught to run good routes and catch the football. Those are the main duties of their position and solid receivers execute those responsibilities well.
Yet, more must be done to make plays at the receiver position.
After securing the football with a catch, a receiver must have the athleticism, agility, vision, instincts and speed to gain additional yards. This is called the "run-after-catch" phase of a play and possessing the skills to excel in this area is key if a receiver wants to be great.
A player in Louisiana does not play receiver on a full-time basis, but has special traits to excel as a run-after-catch player. A running back in Florida makes a ton of plays by taking handoffs, but also shows great ability to gain yards after catching the football. An athlete in California plays on the perimeter, but turns into a running back after he gets the ball in his hands.