The use of loans in football is a divisive topic, with arguments ranging from it levelling the financially unbalanced playing field to conversely being unfair in its application.
It is, though, a key tenet of the football transfer system and for many clubs is a lifeline that helps them ensure that they maintain their standing in the game year upon year.
Some clubs are, of course, better than others at playing the system and indeed some have explored the avenue to such an extent that their whole business is based upon the concept of loan moves.
The concept of building success through the use of loans, though, can be fluid as links between clubs are often dependent on the incumbent manager.
Let's, then, examine some case studies of those using loan moves to their advantage in very different circumstances.
Case Study 1: Everton
Everton have for a long time been a solid top-half Premier League side but have consistently used the loan market well in recent years to consolidate that status.
Given their relative lack of spending power compared to their wealthy divisional rivals, the Toffees have had to be clever in their recruitment strategy over the past decade under both David Moyes and Roberto Martinez.
Moyes was happy to dip into the loan market and did so on a regular basis, with Manuel Fernandes, Landon Donovan and Dennis Straqualursi all having arrived on a temporary basis in the relatively recent past.
Upon Martinez's arrival this summer, loan moves once more were a part of the club's recruitment strategy except in an even bigger capacity.
Both Romelu Lukaku and Gerard Deulofeu arrived from major European sides where they were not yet considered ready for first-team action and have both impressed in the Premier League thus far. Indeed, they have both contributed to Everton's excellent league position.
Per the Guardian's Andy Hunter, Martinez spoke in December of Everton becoming a haven for talented young loanees seeking first-team football and it may well be a strategy that serves them well long term.
With Martinez's connections in Barcelona, Deulofeu may not be the last to follow that particular route from the Camp Nou to Goodison Park.
Case Study 2: Rayo Vallecano
In the case of La Liga side Rayo, most seasons begin with the objective of staying clear of relegation and, in order to do so, the club have been particularly active in the loan market.
As highlighted in a tweet from Spanish football writer David Carlidge, la Liga top scorer Diego Costa, Swansea's Jordi Amat and Everton's Joel Robles are among those to have gone on to better things after a loan spell at the Vallecas club. There are several others.
Currently the club boast five loan players, of whom Atletico Madrid-owned Saul Niguez is enjoying an excellent campaign, attracting interest from Manchester United according to the Daily Telegraph.
@Chris_Elastico I'd say Rayo Vallecano currently utilise loan system the best in Spain, and free transfers even better.— David (@davidjaca) January 15, 2014
@Chris_Elastico Collective loaning has kept Rayo afloat since their promotion. That in itself, given their low budget, a huge success.— David (@davidjaca) January 15, 2014
Others include Tottenham's Iago Falque, Valencia's Jonathan Viera and rising Peru international Cristian Cueva.
La Liga is not as affluent as it has been, but Rayo are certainly among the smaller spenders in the division. Through a careful strategy of acquisitions and loan deals, though, they are managing to stay afloat.
They are far from alone in doing so across Europe, with co-ownerships common in helping lower-ranked Italian sides compete and loans aplenty in the lower rungs of the Premier League. Rayo, though, are stunningly successful.
Case Study 3: Vitesse Arnhem
The Eredivisie resumes following its winter break this weekend and will do so with Vitesse lying level on points with leaders Ajax, having led the way for much of the season thus far.
As discussed by ESPN FC's Mo Moallim, it is a success built on a takeover by a Russian billionaire. However, it is not purely money that has sent the side soaring but more their owner's relationship with Chelsea's own Russian, Roman Abramovich.
Vitesse have become a feeder side for the Blues in all but name, with five Chelsea-owned players currently at the club and a further two only recently departed.
While only Lucas Piazon, Patrick Van Aanholt and Christian Atsu may be regulars, their influence on the side cannot be understated with Piazon in particular excelling. Per Soccerway, he already has 11 goals and eight assists to his name this campaign.
Manchester United have led the way for Premier League sides in terms of benefiting from loans in recent years, with the incredible connections of former manager Sir Alex Ferguson allowing him to place many players in the top two English divisions.
Chelsea, though, look set to reap the rewards of their partnership with Vitesse, with players gaining valuable experience of competing for honours and, potentially, in the Champions League.
For Vitesse, while there will be mutterings of complaint from various quarters in Holland, it is a set-up that is seeing them exceed all expectation.
Case Study 4: Udinese-Granada-Watford
If Vitesse are unofficially Chelsea's feeder side, there can be no pretence about the state of affairs at Udinese, Granada and Watford—all of which are owned by the Pozzo family.
As a regular in the upper reaches of the Serie A, Udinese are the big brother of the partnership with Granada and later Watford more recent additions to the family.
The partnership may not have had a particularly positive impact on the Friuli side thus far, with the club undergoing a poor season this time around.
Does the loan system benefit football?
However, the plan came extremely close to unexpectedly quick fruition last campaign as a Watford side packed with loanees almost sealed promotion to the English Premier League. The financial windfall that would have brought would have seen benefits across the whole operation.
For a club that would otherwise be consumed by their rivals, Granada have managed consistently to defy expectation and retain their la Liga status due to the operation. Now beginning to become established, they lie in the top half of the division with five Udinese loanees among their ranks.
The key to the scheme's success is Watford, though, and the Hornets took on many of 2012-13 season's loanees on permanent deals last summer after a rule change, described by BBC Sport, limited their loan options.
While they appear unlikely to go up this season, it would seem as though they are unlikely to remain in the Championship too much longer if the investment should continue.
If all three sides can establish themselves in their respective top flights and rake in the revenue that in itself brings, as well as Udinese's impressive scouting set-up, the Pozzo family's plans will have come together nicely.