Like it or not, football is a business and part of every business involves making money. Some clubs in Europe are better at this than others when it comes to the transfer market, while some are in a different league altogether.

Since 2010, we've looked at some of the top teams when it comes to making a profit from the exits of their players. Usually, that means bringing in an unknown in for a cheap transfer fee, developing them, moving them on for a lot more, and then starting the cycle again.

While it's possible to make a profit on a world-class star like Neymar -- whom Barcelona signed for €88 million from Santos in 2013 and moved on to Paris Saint-Germain for €222m four years later -- the majority of successful dealings for clubs comes with lower-profile players. And -- spoiler alert -- the big clubs are not usually the ones who benefit in the short term as they are forced to pay more to land their targets.

Here, via Transfermarkt, is a list of those sides who have found great success by making a profit on player trading in the transfer market over the past 12 years.

BENFICA

Record arrival: €34m - Darwin Nunez (UD Almeria)
Record departure: €75m - Darwin Nunez (Liverpool)

Benfica are the best-supported club in Portugal -- they have seven titles since 2000-01 and a record 37 overall -- and have generated more than €1 billion in transfer income over the past two decades.

Benfica's transfer blueprint doesn't differ too much from that of their rivals FC Porto (see below), but it is their top-class academy that, under the guidance of some of the top youth coaches in Europe, has churned out some of the best young players for decades. Joao Felix's move to Atletico Madrid for €126m and Ruben Dias to Manchester City for €68m are the crowning jewels, but Benfica also have an excellent scouting network in Argentina and Brazil that has allowed them to bring players like David Luiz, Angel Di Maria and Pablo Aimar through the club for minimal fees.

In general, Portuguese clubs benefit from a climate, culture and style of football not far removed from South America, which allows for a smooth transition for players crossing the Atlantic for the first time. Being a top team in a relatively wage-modest country (with few restrictions on signing foreign players) also allows Benfica to offer salaries for foreign players at significantly lower terms than, for instance, a Brazilian talent would expect at a club of a similar stature in Italy or Germany.

Yet they are also good at developing talents from smaller European countries like Serbia, Slovenia and Sweden. Nemanja Matic (€5m from Chelsea, then returned to the club for €25m three years later), Jan Oblak (€4m from NK Olimpija, before a €16m move to Atletico Madrid) and Victor Lindelof (an academy prospect who made a €35m profit when signed by Man United.) Most recently, Benfica's ability to spot Darwin Nunez's talent at Spanish side Almeria saw them make a €41m profit in two years when he moved to Liverpool for €75m this summer.

A major strength is also Benfica's ability to position themselves as a "boutique" club (the same goes for FC Porto) who almost exclusively enter and exit transfer dealings on their terms only.

FC PORTO

Record arrival: €20m - David Carmo (Braga), Oliver Torres (Atletico Madrid), Giannelli Imbula (Marseille)
Record departure: €50m - Eder Militao (Real Madrid)

With near-constant domestic success -- 12 titles since 2000-01, albeit in a league with few genuine competitors -- and regular Champions League football, the Portuguese champions have long been a well-oiled machine for profitable transfer operations.

Led by long-serving president Jorge Nuno Pinto da Costa, who celebrated the 40th anniversary of his tenure earlier this year, Porto have been a major player in the transfer market since Chelsea signed Ricardo Carvalho and Paulo Ferreira for a combined €50m in 2004. With Pinto da Costa providing stability and loyalty to the club's model of signing cheaply, developing, moving on and reinvesting, Porto have made maximum use of their ability to pick excellent head coaches, but it is their scouting network that really impresses. Wherever one ventures out on the scouting circuit, a Porto representative appears to be present and the club have particularly strong links to South America.

Porto have used this relationship to bring in the likes of striker Radamel Falcao from River Plate for €5.5m (making a €34.5m profit moving him on to Atletico Madrid), defender Eder Militao from Sao Paulo for €7m (a €43m profit from Real Madrid inside a year) and, more recently, winger Luis Diaz for €7m from Junior FC (a €40m profit from Liverpool two years later.)

Porto have never spent above €20m and have been smart when it comes to doing business in new markets that have come and gone, for example: Hulk and Bruno Alves moved to Russian side Zenit St Petersburg for a combined €62m, which was a huge windfall for the early 2010s. They also have fantastic academy, as shown by the fact Vitinha (PSG), Fabio Vieira (Arsenal) and Fabio Silva (Wolves) have all brought in a combined €116m.

AJAX

Record arrival: €31.3m - Steven Bergwijn (Tottenham)
Record departure: €86m - Frenkie de Jong (Barcelona)

Having ruled over one of the most prestigious academies in European football for decades, the Dutch club still enjoy the position of being as close as one can come to the archetype of an ideology-driven club. The result of years of strategical work, commonly shared principles and methodology anchored from youth development through to senior level, Ajax have supplied world-class footballers who have played key roles in some of the top clubs in the world.

Critics might claim that an Ajax player may not be very adaptable or is too concerned about the aesthetic side of the game, but there is no doubt of their quality. Executives at some of the major clubs in Europe certainly seem to agree as Ajax fetched €112m from departing players this summer: Lisandro Martinez (Man United), Sebastien Haller (Borussia Dortmund,) Ryan Gravenberch (Bayern Munich) and Nicolas Tagliafico (Lyon.)

De Jong (€86m to Barcelona), Matthijs de Ligt (€85m to Juventus) and Donny van de Beek (€39m to Man United) were the jewels in the academy crown of recent years, but Ajax have also shown they can sign from others clubs, especially in the Netherlands, too: Luis Suarez's €7.5m move from Groningen made them €15m profit with his move to Liverpool, while Hakim Ziyech was signed from FC Twente for €11m and moved on to Chelsea for €44m.

Due to tighter restrictions over registering non-EU players in the Netherlands, Ajax may not represent the ideal launchpad for overseas players (though Colombia's Davinson Sanchez, Argentina's Martinez and Brazil's Anthony found success after arriving as rather low-key signings), but the club will continue to be a massive draw for top European talent.

LILLE

Record arrival: €27m - Jonathan David (KAA Gent)
Record departure: €80m - Nicolas Pepe (Arsenal)

Arguably the best provider of underrated Ligue 1 talent to the Premier League over the past decade (think Yohan Cabaye and Mathieu Debuchy to Newcastle; Idrissa Gueye and Anwar El Ghazi to Aston Villa), Lille have recently emerged as an arena for high-end player transfers, aided by their 2020-21 title winning campaign.

Though Pepe's €80m move to Arsenal in 2019 is their record transfer income, the payment was split over his five-year contract and arguably a higher-profile deal came when Nigeria striker Victor Osimhen secured a €75m move to Napoli from RSC Charleroi for €22.4m the same year.

Things have continued in the same vein this summer, as €100m has been raised from deals including: Sven Botman (€37m to Newcastle), Amadou Onana (€36m to Everton), Renato Sanches (€15m to PSG) and Zeki Celik €7m to Roma.) While a lot of the credit for the club's sporting and transfer success is due the main architects of their Ligue 1 success -- head coach Christophe Galtier and sporting director Luis Campos (now reunited at Paris Saint-Germain) -- Lille have always been a much-visited destination for travelling scouts due to the geographical vicinity to the capital city Paris, England (a train journey shorter than a game of football) and neighbouring European countries.

Lille have managed to retain good relations with Premier League clubs via previous dealings or agents and also, rather impressively, have remained competitive through what seems like endless periods of transition and boardroom turbulence (the club changed hands as a result of the collapse of the Ligue 1 media deal two years ago.)

Botman replacing Arsenal-bound Gabriel and Jonathan David taking over from Osimhen -- with both proving pivotal in the club's title-winning campaign in their debut seasons -- gives an idea of how a club can remain competitive even when they often move on their star players for a profit.

FC SALZBURG

Record arrival: €13m - Lucas Gourna-Douath (Saint Etienne)
Record departure: €32.9m - Brenden Aaronson (Leeds)

Once the starting point of what is now a worldwide network of clubs under the Red Bull umbrella -- from which RB Leipzig represents the top of the pyramid -- the Austrian champions have excelled in the transfer market over the past 10 years. They have had a remarkable number of top-class young players arrive looking to find their feet in the relatively gentle sporting environment of the Austrian league before moving on to bigger things.

Aaronson (€32.9m to Leeds), Erling Haaland (€20m to Dortmund), Karim Adeyemi (€30m to Dortmund), Patson Daka (€30m to Leicester), Sadio Mane (€23m to Southampton), Enock Mwepu (€23m to Brighton), to mention just a few, are clear proof that the club's scouting team is of the highest order when you consider the minimal fees they were signed for. It's incredible that €13m is still their record incoming.

The whole RB recruitment team is managed according to clear principles of what represents the makeup of an ideal recruit: physical strength, explosive pace and power, stamina suitable for pressing, and an aggressive playing style, which all rank highly on the checklist to narrow down the search for potential stars.

Having Leipzig as an affiliated club in the upper echelons of the German Bundesliga is also a major pull for prospective signings. Since 2010, more than 20 players have taken that well-trodden route including: Naby Keita (€30m), Dominik Szoboszlai (€22m), Amadou Haidara (€19m), Dayot Upamecano (€18.5m) and, most recently, €24m striker Benjamin Sesko. Salzburg may not be the ones to make the big profit when Leipzig move them on to bigger clubs, but the Austrian side have done well to feed them talent and have certainly benefited as a result. They are now a favoured scouting destination for clubs aspiring to play a similar brand of football.