It is no secret that
The folks at EyeSeeData.com put together a video that shows the history of player transfers over the past 133 years in just 60 seconds. Player transfers is the process by which a player's rights are sold from one club to another.
As recently as 1963-64, only 13 countries were involved in international transfers with fees totaling $633,000 ($4.8 million in 2013 dollars). In 2012-13, 167 countries were involved in transfers with fees totaling $2.7 billion. You can see an interactive map at EyeSeeData.com...