A word of advice to every Premier League club - if you're looking for a blueprint on how to operate in the transfer market, check Chelsea's.
The 2015 winter window was another huge success for the Blues. While they managed to secure the exciting prospect of Fiorentina winger Juan Cuadrado on deadline day, it's the continued ability to command premium price for players of their own that's allowing them to take significant steps forward as a business.
Since Jose Mourinho returned to the club in 2013, the trend has started. The Portuguese tactician began by offloading a number of players for free, but it's been the last three transfer windows that have been their resounding successes.
Raking in £37.1million for Juan Mata from Manchester United in January 2014 looked a great transaction - especially considering the Spaniard was on the periphery of Mourinho's first choice team. Chelsea worked their magic last summer too, but the fact the club managed to turn profit on German forward Andre Schurrle most recently is mind-bogglingly good business.
Schurrle's scoring record of 14 goals in 65 appearances was decent if uninspiring, but since his arrival in 2013 the former Leverkusen man's role had been that of a benchwarmer. Willian has kept the 24-year-old out of the team more often than not and Mourinho had displayed in recent months that he wasn't greatly impressed with Schurrle's work rate.
Dependent on your source, Schurrle left for between £22million and £24million, representing a healthy profit from the initial £18million the Blues laid down for him when he signed. Throw in the fact that Ryan Bertrand was sold to Southampton for £10million and there was money for Cuadrado in the coffers, with some to spare.
But somehow, Chelsea have turned a profit and strengthened their squad simultaneously. Talk about knowing how to operate around Financial Fair Play. This is the perfect example.
Chances are that they'll continue to execute their ideas to perfection over the coming windows, but don't be surprised if Schurrle ends up as an exception to their current rule. Chelsea's unwavering insistence on 'stockpiling' young players is where their future money will come from, but for the likely future offloads of Petr Cech and John Obi Mikel.
After all, Chelsea have around 30 players outside of their first team squad on loan with other clubs. Realistically, more than two thirds of those players will never make it to the club's first team. And that's being generous.
Instead, their operation is thought through to a tee. It's smart, there's no escaping that and as long as there's no policing from footballing bodies on how many players can be loaned out at once, the Premier League leaders will continue to harvest the benefits.
Essentially, Mourinho is playing the Football Manager game with real people. It's a foolproof plan and the easiest way of turning up money to improve the first team squad. To sustain success, you've got to build for the future - but Mourinho's masterplan is to have that luxury underneath his cream of the crop.
It's a cycle. Identify young player, sign young player, send out on loan. If he doesn't make it, sell him - with the likelihood being that his regular exposure to first team football has driven his value up somewhere else along the way.
There's two cases in point that jump up the highest. Kevin De Bruyne, while he is admittedly showing his worth at Wolfsburg - recently joined by Schurrle - spent time out on loan at both Genk and Werder Bremen after signing for Chelsea. Signing for just shy of £7million in 2012, the club would make a £10million profit on the Belgian just two years later.
Romelu Lukaku followed a similar path. He was signed for £20million and spent time on loan with West Brom and Everton, before the latter shattered their transfer record to sign him last summer for £28million.
Chelsea's transfer strategy is long term and it's such a strong blueprint that it's going to keep them at the pinnacle of English football for the years to come.
So who's next in line? You only need to look at Chelsea's list of players currently out on loan to realise where the money will come from. Marko van Ginkel has had a nightmare with injury troubles to date and he's currently out at Milan - though he'll need some regular football under his belt for Chelsea to maximise his fee.
Think Lucas Piazon, Christian Atsu, Victor Moses. Even Patrick Bamford, Eden Hazard's brother Thorgan and recent departure Mohamed Salah. Realistically, each player will never establish themselves in the Chelsea first team and will inevitably find themselves permanently transferred out when it's financially viable for Chelsea.
While football is a sometimes cruel, cut-throat business, it's worth remembering that a business is exactly what it's become.
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