Yeah, imagine this, its November, its freezing, weve just lost 1-3 at home to a promoted team. Half the Park end and Gwladys who wouldve been in the Brick by 74 mins are gonna stick around to watch a glorified open mic night in a stadium concourse, still fuming at what they just witnessed. People who have a 2 hour journey back to Wales or the midlands are gonna say, "Nah, we might as well stick around in the stadium to watch Southampton vs Spurs on the 17.30 game", thats even if the are allowed to broadcast it.
Its fanciful and pie in the sky and depends on numerous factors that simply cannot be controlled, even if they serve food and drink at regular pub prices.
At best, they can leave the concourse open past half time to full time, and hopefully get a bit more business, and they might be able to serve more people in a faster amount of time, but a lot of people who wont pay £10 for a pint and a cardboard sausage roll arent going to pay £20 for a pint and a Halloumi wrap.
Keeping people behind would need some proper planning and thinking, like building a series of designated pubs and restaurants in the vacinity that the club own and run or lease to other businesses.
Existing pubs should do ok out of it like, and Costco is gonna be a nightmare from 5pm onwards on Saturdays.