Companies (and rich supporters like Noel Gallagher) buy a box like a season ticket.
The companies then invite guests/clients and the match decides which clients they invite. Company I worked at had a block of premium seats at new Wembley, Millenium Stadium, Murryfield, Old Trafford, and iirc, The Emirates.
I got to use the Millenium Stadium one for the very first match, (good clients), and the OT ones for me and my mates for an FA Cup 3rd Round against Sunderland! (Not PL Sunderland!).
interestingly that market is retracting quite a bit as companies tighten up on "gifting", again the idea of a premium seat and a posh IPA is probably a better solution for many big companies, where the guests are corporate clients.