I agree with the Captain. Another rule of thumb is, if you have ask to perform it's a floorspot.

To be a support act you would have to be invited in advance, and be advertised as such in the publicity. It should probably be paid, although in some circumstances it might be done just for the publicity.

A floorspot is never a "gig" and should never be described as such, and to try to claim some reflected glory from the booked guest who happesn to be on that night is just dishonest.

In my experience proper support acts are fairly unusual on the folk scene, most clubs seem to manage well enough with residents and floor spots not to need them. Or more likely, they can't afford to pay two guests on a single evening. Either way, anyone claiming to do a lot of support acts is probably being misleading.

Girl Friday, doing regular floor spots at a club will be good experience but worthless as publicity, he should follow Tabster's advice and go round a lot of clubs doing floor spots, making sure they're aware that he's hoping to get a gig out of it (without being too pushy)