Tied pub' gross profit margin on draught beer typically is around 35% - 40% - not enough to make the business able to cover overheads unless it is really bust and there's enough of a cash margin over the year to do better than break even.
This is why, excessive rents aside, there is so much business failure in the pub sector - the majority of pubs are tied = the majority of pubs are continually in a spiral of business failure. They only stay open between one tenants' failure and the next tenant investing in the premises as pubco's use 'Holding Companies' to trade the pubs while being marketed between tenants...
It's called the #GreatBritishPubcoScam
Thanks for listening