The Rams selected Tavon Austin in the first round of the NFL Draft in order to help the devolpment of Sam Bradford. They then got Bradford more help at the end of the third round by taking Austin's college teammate at West Virginia Stedman Bailey. Bailey is a fantastic route runner and forces defenses to defend him outside the numbers.
Even with all his physical traits, the pick of Bailey is more about combining him with Austin than anything. Being able to get an all-around player and a legitimate outside option for Sam Bradford instantly makes the Rams offense more dangerous.