Big European nights at Old Trafford act like chapter markers down the eventful, controversial, trophy-strewn, debt-laden Glazer years. From victorious semi-finals against Barcelona and Arsenal that allowed the Glazers to claim they were continuing to deliver on the pitch while loading the balance sheet with debt, to the last-16 tie with Milan that was swathed in green and gold and marked the high watermark of fan protests, they have tended to accentuate the prevailing mood off the pitch as well as on.
This week's clash with Real Madrid feels similarly epochal. If things do not go United's way, it could be the final Champions League match that David Gill watches as chief executive, ahead of a summer that will usher in a new phase of the Glazer era and a renewed push to further turbocharge the extraordinary commercial growth overseen by the man who will replace him.
The recent Deloitte Money League, an intriguing if imperfect barometer of financial muscle, underlined the extent to which Real Madrid (£480m annual income), Barcelona (£451m), Manchester United (£367m) and Bayern Munich (£321m) were in a league of their own when it came to money-making potential.
The United model, formulated by the vice-chairman Ed Woodward, who will take on Gill's responsibilities from the summer, and Richard Arnold, the commercial director who has earned a promotion to group managing director, is looked on with envy even by the two Spanish giants, who are trying to follow suit. But because the Spanish big two keep the majority of their TV income, in contrast to the Premier League where domestic rights are shared more equally, United have to pedal ever harder to catch up with Real, who remain at the pinnacle of the highest earners in European football.
For Manchester United, that has meant slicing and dicing commercial partnerships around the world in a series of "verticals", and there is still plenty of room for growth – they believe there are up to 90 or so deals that can be targeted. Some of those, such as mobile telephony, have been hived off to sell on a regional basis, bringing in vastly more revenue than a single global deal.
United's nebulous claim to have 659m "followers" around the world is easy to mock, but there is a long queue of brands, many with names unknown globally but huge in their domestic markets, still lining up to tap into the club's heritage.
Woodward told the Guardian last year that the strategy was "not even at base camp" and that the only limiting factor was if they had enough staff to service the deals and enough former players signed up as ambassadors to gladhand sponsors.
In the last quarter alone United signed deals with the Japanese paint brand Kansai, Singha beer, Chinese soft drinks company Wahaha, Indonesian tyre manufacturer Multistrada, the China Construction Bank and the Turkish Denizbank. Those second-quarter results showed commercial revenues had increased 29% year-on-year.
The scramble for global commercial deals has long been characterised as an arms race between the biggest clubs in Europe. But in reality, international revenues remained tiny compared with matchday and broadcast income until relatively recently. It is the path forged by Woodward from United's London office that has made it a major contributor to the bottom line of those handful of clubs and his ascension to the top job is likely to see a further acceleration.
In an era of Financial Fair Play in Europe and the new Premier League financial controls, all the commercial income that is added to Manchester United's bottom line will take them further away from the domestic competition and closer to catching Madrid.
The club's new shirt sponsorship deal with Chevrolet, worth $559m (£370m) over nine years from July 2014, will also help open doors in America, where a New York office is due to open to complement existing bases in London and Hong Kong. Negotiations have just begun on the renewal of Nike's kit contract in a deal that could be worth as much as £1bn over 15 years.
A new media strategy should boost revenues and fan engagement across the world. The vision is to tie up deals around the world with mobile phone and media partners, which can be furnished with exclusive content in a myriad of languages.
As Woodward has proved his commercial mettle, the amount sucked out of the club in fees and interest is predicted by the financial analyst Andy Green, who has chronicled each twist of the Glazernomics experiment on his Andersred blog, to hit a staggering £1bn by 2016. But by that point it is also entirely possible that United's debt will have been eliminated altogether as a result of the soaring commercial revenues, the Premier League's bumper £5.5bn TV deal and the new financial regulations, which should help temper wage inflation.
Much of the build-up to Tuesday's match will be dominated by the return of Ronaldo to Old Trafford. A renewed bout of speculation has surrounded the unlikely prospect of making it permanent, and here too commercial considerations could come into play. Woodward, whose biggest task in his new role will be replacing Ferguson when the time comes, has previously said that the club will require a net transfer outlay of only £25m a year to continue to compete. But the capture of Robin van Persie last summer showed they were prepared to make exceptions to their policy of signing younger players whose value would appreciate. If nothing else, an audacious bid to bring Ronaldo back to Manchester would play well commercially.
Gill, who is stepping down after a decade as chief excecutive to concentrate on his campaign to win a spot on the Uefa executive committee but will remain a director, would accentuate the extent to which the club has managed to maintain its traditions while walking a financial tightrope. The more they chase riches abroad, the more estranged United's match going fans could feel. But the simple truth is that, if they carry on winning, most are unlikely to care.