I have played in a few places here in my my town, just me and my guitar. The usual, churches, the coffee house, bars, weddings, funerals, the local County Republican Ladies Club's Christmas party!? (it bought dinner), on the court house lawn at the Christmas parade and 4th of July, etc.
The band has played at festivals and churches.
For me the special moments are when we're told by folks that our originals are their favorites.

I can't accurately speak to the impact it has on the industry as a whole but for a band there are many affordable promotional benefits. For people like me it also provides an opportunity to be involved in ways that would otherwise be impossible. I can make contact with other writers, have my songs heard and hear songs by others, seek advice, give advice (it could happen), collaborate, critique, etc.

yes