Barcelona GM Pep Segura admits selling players is now part of their business model.
Barcelona spent €125m and brought in €82m last summer.
Segura told Sport: "Increasingly the business of football is based on the buying and selling of players. Depending on how that's managed we'll have more or less sporting and economic success.
"To give an example, look at the young players who are more and more in a hurry and have more options to leave. This means you have to have clear planning ideas in the short, medium and long term."