I'm not entirely sure that a performer who books into an arts centre or other larger venue will necessarily pull a bigger crowd. When Jez Lowe performed at the City Vatieties in Leeds he played to around 20 people. Whenever he plays at the Grove Folk Club, in the same city he fills the room (65-70 paying punters). Ho hum.

A local venture that has taken off is the concert series at Saltaire Town Hall but they book guests that get pushed by Mike Harding and Froots (Sharon Shannon, Dervish, Lunasa etc.). It's a successful evening but they haven't, as yet, taken a punt on yer typical folk club guest.

As to singarounds, locally, at least, they are flourishing. Places like Korks, Otley and the Abbey in Leeds are packed with singers and musicians (and people who just come to listen, funnily enough) every week and are consistently exciting.

I reckon anywhere that allows live music ought to be encouraged. Try a venue out, if you like it, tell your friends, if you don't, don't go again. Easy, really.