I visit reading groups. I don't even wait to be asked. I'll ask myself.
I go because they are readers, and not just readers but people with a real love for it. It may interest them to meet the author of the book they've read. It certainly interests me to hear what they have to say. And I don't want them to be polite.
Well, of course I want them to be polite. I want them to have loved the book and recommend it to all their friends. But mostly I want them to talk to me about how they've reacted to what I've written. In reading, the reader re-tells the story to themselves, using the materials the author has given them. Sometimes it'll work for them and sometimes it won't. If it doesn't, they should not be afraid to say so.
A reader is never wrong about how they respond to a book. They may have read it differently from the way I intended. They may be irritated by things I thought clever. I've had chunks of my work read back to me in tones of mild scorn, followed by the question 'why did you write it like that?' And once one starts others will join in. About half way through a session I'll probably be thinking 'Oh my God, none of them liked it!' But what one doesn't like, another will. All readers are different.
Reading groups differ too. Some are all young mothers, others are retired couples or work colleagues. Some groups are dominated by a few individuals. Others are more collegiate. You don't know what you are going to get when you go in. But if it goes well I'll be left with a buzz and maybe they will be too. And then I can return to the work that I'm currently writing and think, with my fingers over the keyboard - 'now, how would I interest that lot in this?'