You could always count uniteds commercial success off the pitch and also outside of the UK as thier sugar daddy
In the end whether he'd bought city, or one of the other clubs he was looking at (newcastle, everton...etc) it will make the premier league more interesting....
What's the point in having a commercial success if on the field you've already bought all the good players that no-one else can afford which means that you dominate by default. Makes the game very boring....
Also if it fails for the "nuevo rich" then quite simply you have better gloating rights....