Oh, hi, Villan. That is a great question and one worth pondering. I didn't book these gigs, but I'm trying to book a US tour for Jeff right now, and here are some of the elements I've been dealing with.

1. The artist is travelling from afar, needs as many gigs as possible in a relatively brief time, and takes everything offered.
2. The club hosts are informed about the possible conflict, but do not feel that it IS a conflict, and agree to the bookings.
3. Sometimes a given date (let's say a Saturday) is quite busy with a variety of entertainment available, but a date only a few days later (say, a Thursday) has nothing much on. The thought is that those who chose something else on Sat will come out for this artist on Thurs. A kind of spread-the-wealth mentality.
4. Sometimes, the first gig offer is for a relatively small amount of money, but one takes it, to have a gig. Then, 2 weeks later, a large gig offer comes in. Well... you don't say no.

All of these things have happened with the tour I'm working on. There are other issues, I'm sure. One way to go is to let the artist decide FOR the club owners what constitutes a conflict, and refuse to take another gig within, say, an hour's drive. This brings a conflict with No. 1, above, though.

Anyway, I'm glad you'll take in one of Jeff's shows in your area. Don't be too hard on him! He did not make the bookings. But he's happy to be there, and to meet other traddies and lovers of folk song.
Barbara