Goal Transfer List 2014: As is often the case, it takes just one mega deal to trigger money being fired in multiple directions within the football marketplace
The biggest transfers in world football in 2014 helped spark numerous mega-money deals as, once again, it was shown that the marketplace works like one colossal chain reaction.
Take the most expensive signing of the summer: Luis Suarez, for example. Part of the reason why Barcelona were able to spend an estimated €81 million on the Uruguayan striker was that they had been handed €37m for Cesc Fabregas and €40m for Alexis Sanchez.
But would Fabregas' arrival had been possible had Manchester United not sown the seeds in January with their purchase of Juan Mata? Potentially not. Similarly, Mario Balotelli would never have been bought if Barca hadn't stolen Suarez away from Liverpool.
Of course, some clubs do not need to raise funds to justify big spending in the modern game. Paris Saint-Germain are a growing club who have shown ruthless expenditure in the transfer market in recent years.
Although they were low-key in terms of the number of player signed ahead of the 2014-15 season, their mammoth €50m bid for David Luiz helped to facilitate a number of high-profile moves.
Chelsea immediately invested most of that cash in Atletico Madrid star forward Diego Costa, who has in turn proved his value by scoring 12 goals in 13 Premier League appearances since his arrival.
A striker who subsequently benefited from PSG's wealth and Chelsea's quick-spending was Mario Mandzukic. Faced with being benched at Bayern Munich following Robert Lewandowski's free transfer, the Croatian was targeted by Diego Simeone as the striker to fill his Costa void at the Vicente Calderon.
The Croatian's now-former club, Bayern, lost Toni Kroos to Real Madrid but losing a World Cup winner for €30m simply allowed them to recover bring in centre-back Mehdi Benatia (€30m) and Xabi Alonso (€11m).
Manchester United were at the heart of so many chain reactions in the window in 2014. Rocked by faltering form in January, they splashed on Mata, but it was their enormous output in the summer which shook up the market the most.
At the epicentre of their spree was the €75m purchase of Angel Di Maria from the European champions, which in turn helped Real Madrid to balance their books after buying James Rodriguez (at €80m from Monaco, the second-most expensive up front fee for a footballer this year).
Transfer deadline day wasn't without it's own Man Utd swap-of-sorts: Radamel Falcao's loan arrival (which involved a cash payment of €8.5m) meant Danny Welbeck was considered deadwood at Old Trafford, allowing Arsenal to swoop for €22m.