The xenophobes on the other side of the city might bleat on about most United supporters coming from anywhere but Manchester. The hard truth is that City will never be a world leading club until they can attract a global following like Liverpool still have.
It is not something you can get overnight, nor even something money can buy. United surveys suggest they have 659 million global followers. Of course that figure is open to conjecture. Does it mean people who watch their matches or buy their merchandise?
Whatever the number, the hard truth is that Manchester United is probably the most widely supported club across the world. I travel widely on my holidays and the evidence is always there.
Passion and loyalty at the Paradise Hotel
I've just returned from a holiday in the Oberoi Hotel, Mauritius, one of Trip Advisor's best hotels in the world for 2013. This is the nearest thing to paradise on earth I have ever stayed at. It is private and fairly remote but even in this location in a tiny far-off country, the evidence is beyond question that Manchester United are No.1.
Wherever I travel I routinely take at least one Manchester United shirt, knowing it will attract attention. In the streets of Milan that would probably be unwelcome. In Mauritius it was a beacon.
The shirt always draws comment, both from customers and staff. Only one Englishman commented on it. "You support United; I thought you knew something about football."
But it drew endless comments and attention from the staff. There are well over 100 members of staff, from gardeners to general managers and the one consistent topic of conversation every day was Manchester United.
Almost everybody seemed to mention them.
I asked one of them if anybody supported another team. "There are a couple of Liverpool fans; and one Chelsea, but mainly we're Manchester United."
Departing on 12 February, the only topic of conversation since the Sunday had been that the Premier League title race was over and would United now beat Real Madrid.
For anyone who thinks that the hysteria of fans when United tour the Far East for example is stage managed, they might like to take account of this one small example.
In a hotel with 100 luxury bedrooms and 100 staff, at least a quarter of them openly stated their loyalty to United from breakfast through the day to dinner. Once they found out I had a season ticket at Old Trafford they only wanted to talk about the team.
These are not sycophants, serving a client. These are men, young and older, with a fierce passion and loyalty to United.
Intelligent and knowledgeable
Let's be clear. This isn't a shallow adherence just because United are all over their TV screens every match. They have supported United all their lives. Their family supports United, their fathers, uncles and cousins do.
Why do they do that? I asked a few of them.
Shaan would engage me every mealtime about United. He is fiercely proud of his allegiance. "How did you come to support Manchester United, Shaan?"
"My father supported them. He can remember the Busby Babes. He told me all about the great players of the past and the traditions. My uncles, cousins and my whole family support them. Tomorrow, for the Real Madrid match, 14 of us will gather with a few beers in front of the TV to watch the match we've all been waiting for."
"Whose shirt do you wear?" I asked. "Wayne Rooney, of course, but my one-year-old daughter has Robin Van Persie's shirt."
"But what about the other night, the Everton match, which was on while you were working?"
"There is a TV in the staff room. We were all in and out watching it all night. There were 18 of us."
And Shaan is not alone. One of his colleagues could reel off masses of facts from over the years that put me to shame. He was only in his early 20s.
"How do you know all that?"
"When I go home, everything is about Manchester United. I got it from my father, all the way back to the Busby Babes. I've read your column on Bleacher Report last night."
Comparisons between United and one of the best hotels in the world
It's interesting to compare the attitudes that make a great football club and a great hotel. Robin Van Persie's recent interview on MUTV gives an insight:
“Everybody wants to help each other. Everybody's keen for everyone to score. Defenders are working their socks off for the midfielders, the midfielders are working for the strikers... everybody wants to run and everybody has one target in their mind."
This is the same attitude that pervades the staff at this great hotel. They are all pulling for each other, with only one goal in mind: world class customer service.
Recent arrivals Van Persie and Michael Owen have both previously commented on how friendly everyone is at Old Trafford and how everyone made them feel at home.
That's pretty much the secret of a world class hotel.
The staff are ordinary people, but they give extraordinary service, every minute of every day. They make you feel special and that is Sir Alex's secret.
One of the Oberoi's senior managers, Rahul, had a more serious approach to United. He was more analytical and correctly predicted the result of the Everton match. Like his younger colleagues he has supported United all his life.
He is the Sir Alex at the hotel. He went out of his way to find out people's special preferences and simply made them happen. You liked particular Indian dishes? The following night you had a specially prepared meal consisting of all your favourites.
Managers like that have the special knack of bringing the best out of everybody, whether their colleagues or the clients. You can't buy that skill. You are part born with it and you have to work hard at it every day. Sir Alex does and he also makes everyone feel special.
But Shaan is more like the Wayne Rooney. He is solid and strong. He works his socks off every second of the day. He does what is needed and goes the extra mile. For the client and the team. "Aren't you finishing at four o'clock?" "That's OK Mr Carroll, I'm here until you're finished."
If Paradise was designed by Heineken, it would be the Oberoi in Mauritius with all its Manchester United fans on the staff. They will all have been in front of "the box" on Wednesday.
With the service they give, their humility and devotion to the task they have in "paradise", they deserve to go to heaven.
And when they get to their version of heaven they'll find that United have won the Treble again!