Thinking about it, I suspect there's more to it than this. At the AFO conference in 2011 there was a discussion re the power of headliners to attract footfall. It was pointed out that people will go to their favourite festivals whether anyone is booked or not. In fact a number of festivals have risen from the ashes of organisers pull-out simply by the determination of the punters to have a festival in that place on that date. At the AFO it was agreed by a panel of fairly heavy-duty festival organisers, that headline acts possibly account for £0% of sales tops. In the case of Whitby Folk Week, there are no headliners and people start queueing on the last day for advance tickets for the following year.