Over 3500 festivals of various kinds are announced each year. Less than 2000 actually happen and only 1200 make enough money that they are repeated the following year. Festival promotion should be top of the list of activities rather than left as an afterthought
The cost of putting together the stage, security, sound and lighting systems, toilets, water, first aid, policing, parking, council clearances along with all the specialists that are required to operate them (Even if they perform their jobs for " Mates Rates") soon builds up, and even if the non-headline acts perform for free, the costs still build quickly
Because there are so many festivals, having a distinct offering is essential - yet another 80's revival festival, or a real ale event probably won't cut through the noise being generated by the other festivals in the locality
To repeat something that we often say, all the profit is in the last 10% - so maximising numbers is essential. Not only that, but the news of a half empty festival will go round like wild-fire , and will kill any chance of the next year happening, as people who have been to this years festival won't want to go again