Absolutely
There was a great article posted on here a few months ago which explained this
Remember united (and any other club) only sell shirts from their shops. The rest of the sales are by other retailers who have bought the shirts from Adidas
If united make £20 profit per shirt, to make their money back on Pogba they would have to sell four and a half million shirts from their "megastore" or 900,000 per season over his five year deal
That's just Pogba. It's the same figures for Lukaku, so 1.8m shirts per season sold by united
United get a fortune in sponsorship from Adidas, that's where the money is. Not retailing shirts
But the argument to counter this is that the majority of rags would buying these shirts would have done so anyway regardless of whether its Pogba on the back or fat Phil on it.
The 1.8million fans who decided to go and buy a shirt because they just bought Pogba are not all new fans.
Granted there are some fans like that just like the ones that (probably rags) who went out and bought a Madrid shirt because they signed Beckham.