I've done some freelance work for one of the larger UK folk festivals. The people who organise it do so because it's their job, not because they are folk fans. So I suspect they are quite reliant on agents like Alan Bearman to find suitable artists, especially when it comes to international acts.

They also have partnerships with arts organisations in other countries that sometimes seem to result in quota bookings of artists from those countries. That hasn't always worked out well.