Manchester United commercial director
Arnold has been responsible for implementing the groundbreaking 'territory specific' approach to sponsorships that last year enabled United to become the first club to break through the £100million ($A152 million) barrier for annual commercial revenue alone.
Those figures are certain to increase even further in the coming years.
Twelve months ago, United signed a £40million ($A60.8 million) four-year deal for DHL to have its name emblazoned over its training kit, whilst only last month, US car maker Chevrolet paid an estimated £357million ($A542.7 million) to become the Red Devils' shirt sponsors for seven years from 2014.
Underneath that are numerous minor partners, either in individual countries or certain products - sports betting company bwin are the latest - who have paid a sizeable sum to cement a 'partnership' with the Old Trafford outfit.
It is clear maximising these revenues was part of the grand plan when the Glazer family completed its controversial takeover in 2005.
But listening to Arnold, it is clear there is much more to come.
"We are still a comparatively new team," said Arnold.
"We have been working on this for three or four years and have recently opened an office in
"We have a very good track record in mobile and new media. We have 27 million fans on Facebook.
"But in many areas we are just starting and are very early in our development.
"There is a huge amount of work ahead in making sure we make the most of what this club merits."
There are those, particularly in the anti-Glazer camp, who feel the approach diminishes United's status as a football club.
Yet is seems such an approach to commercial opportunities will become the norm, certainly amongst the biggest clubs, with the greatest fan bases.
Earlier this year, Arnold claimed United had 659million followers worldwide.
The information was greeted with immense scepticism by many long-standing - and more local - fans.
But to companies like bwin, the figure carries resonance and explains why, though they are shirt sponsors of Real Madrid, they feel a tie-up with United offers something different.
"Manchester United is one of the biggest sports brands in the world, and I am not talking just about football," said bwin co-chief executive Norbert Teufelberger.
"In terms of the followers, Manchester United are still the biggest.
"It was well documented in their public statements - 650million fans. Real Madrid is 300 million. There is a difference, particularly in their exposure to Asian markets."
Yet it cannot be ignored that Arnold and his commercial team are doing their work against a simmering resentment of the Glazer family.
The recent IPO in
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However, he views the opposition as a by-product of what he feels is United's greatest strength.
"There is a huge spectrum of emotion that comes with the club," he said.
"I wouldn't complain about any part of that spectrum because one of the things that sets us apart from anyone else and makes us the club we are is the passion our fans have for it.
"There is a multitude of ways that passion gets expressed.
"There is a flag in the stadium 'Manchester United, kids, wife - in that order', through to the feedback you get from blogs, both criticism and praise.
"When you are at the biggest club in the biggest sport in the world, you are always going to get it."
Clearly though, Arnold feels the structure of the club is geared towards long-term, sustainable success.
"Anyone that has knowledge of these things would see there is a very strong business at Manchester United," he said.
"The business model we have is to make sure we are successful off the pitch so we can continue to invest in the biggest stars in the world on it.
"That has been proven to be successful.
"It is very important to us to make sure that there is a healthy relationship between those two things."
English Premier League
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