Never understood the cancelling due to low numbers , fair enough if it’s only two or three booked on but ultimately money is money and most sites still have to pay a ground rent so even running at a partial loss is better than a complete loss .
In my experience cancelling due to low numbers is mostly translated to “can’t be bothered” , which usually echoes through the site when it is open as well .
Money is money, and a little bit of incoming money does chip into the fixed costs
But a little bit of income could be a loss against the variable costs - the obvious one being staff - a game should have a minimum of two Marshalls, increasing in line with head count. You could ‘get away’ with one minimum wage zero hour contract Marshall for a tiny walkon. That’s going to be say about 7 hours for 9am to 4pm, add on an hour or two for arrivals and departures (ignore setting up and shutting down)
9 hours of minimum wage, for one young adult is £90
If it’s £20 entry, then 4 players leaves you at a loss for the day with only one member of staff on site, or break even with 9 players and two staff - plus they have to either turn up or to have paid a non refundable deposit
For good faith a business may do this as a loss leader providing it is occasional
(Take note that there has been at least one fatality in the UK with a paintball site that had one member of staff working alone, she was trapped when unloading a van. This was at a site managed by a national company with a lot of financial backing)
A common Airsoft answer to that may be unpaid ‘player Marshalls’ - that enables a walkon etc to happen, but is a poor business model and can be a factor for non profitable sites run badly / unprofessionally
There is another variable cost that some sites may have.
One site we ran events on had a day charge from the landowning farmer - if anybody was on site at any time there was a charge.
Our typical event day would be a Sunday, that meant our main pre setup could be done on Saturday, just worked around rental players in each of the zones. But we would also build new constructions, (in theory benefiting an evolving site for players to come back, but some was in between zones or in in abandoned zones as we would use as much of the land as possible so those may not benefit standard play)
The extra days or evenings in the week cost them money - it also made them money from the event, but there would have been more money in the pot if it wasn’t paid to the landowner