If I get a request from somebody wanting a gig, I at least have the decency to reply back and say yes or no. Most often, it is becuase the act does not suit the style of my venue or who I want to put on. I explain that.
However, I get a lot of artists asking me for gigs, who are not folk and haven't done their homework on who and what my venue does. For those I just delete them. I find those post as spamming rude.

Just bear in mind, that many organisers do not want to say no, but some find it very difficult to say no, so they delete and don't get back.

Nothing is final until the organiser responds saying yes. Those need to go on your backburner, and if something else comes up in between, then phone the organiser telling them that you have had another offer for that date and you would like to take that if they can't take you on.