Let’s get straight to the point. Prior to this latest transfer window, Borussia Dortmund had made €994m from selling players in just nine years!With the latest Niclas Fullkrug’s move to West Ham for around €25m they’ll broke the one-billion-euro barrier in player sales since 2015.But how do they do it?It’s very simple – they acquire talented youngsters for very little money, and then they work on the players’ development and then offload them to the biggest clubs for sick numbers.According to BILD, Jude Bellingham’s move from Dortmund to Real Madrid last year was worth more than those initial €103m. The sum increased to €113m because Bellingham activated add-ons worth €10m after the first season.If Jude wins the Ballon d’Or by the end of his contract in Madrid, the transfer could ultimately amount to a maximum of €134m.Compared to Bellingham’s deal, selling of Erling Haaland year before that was not nearly that lucrative though. It brought the German side only a 1/3 of Bellingham’s money despite the fact Haaland was a goal machine, scoring 86 goals in just 89 matches for them. Still, it costed Manchester City more than €50m to aquire the BVB striker.However, Dortmund should be mostly proud of the deal involving Ousmane Dembele.He left the Bundesliga side for Barcelona in 2017 as a 19-year-old, only a year after arriving at Westfalen.BILD are now suggesting the final fee for Dembele’s transfer was €148m, making the winger the third most expensive signing in history of football behind Neymar Jr and Kylian Mbappe, who both moved to Paris Saint-Germain in 2018.Dortmund’s sales strategy should be studied at universities, and those figures prove it.BUNDESLIGA – MATCHDAY 3Friday 21.30: (1.45) Dortmund (4.50) Heidenheim (7.00)Saturday 16.30: (2.85) M’ gladbach (3.60) Stuttgart (2.35)16.30: (1.70) Freiburg (4.00) Bochum (4.80)16.30: (5.80) Hoffenheim (4.30) Leverkusen (1.55)16.30: (1.50) RB Leipzig (4.40) Union Berlin (7.50)16.30: (2.85) Wolfsburg (3.50) Eintr.Frankfurt (2.60)19.30: (11.0) Holstein Kiel (6.75) Bayern (1.23)Sunday 16.30: (2.05) Augsburg (3.45) St.Pauli (3.60)18.30: (2.10) Mainz (3.50) Werder (3.80)***odds are subject to change***