It has actually been down to the professionals to promote themselves,[e. g.Jez Lowe amongst others, sending out a monthly circular to his fans as to where he will be playing].when it should actually be the organisers responsibility.
other pros,pay for space with adverts in folk magazines,some like myself use the internet to promote ourselves.
when I first started going to folk clubs they were all full,regardless of the guest,most clubs had a membership system which encouraged,people to come back regularly, once they had joined,the organiser had a list of names and adresses.
So the organiser, knew, who in his locality was interested,and could contact them to find out why they were NOT coming any more,or to keep them informed of future events etc.http://www.dickmiles.com