"Have you read this?"
"No but I've heard it's really good."
"What can you tell me about this one?"
"Not a lot. I haven't read it myself but have spoken to a few people who have and they loved it."
"Do you even read?"
"...."
Ok so that last one never really happened. But the other two happen, saddly quite a lot. And it is awkward. When someone asks you to give a recommendation for a specific book and honestly, you've never seen that book in your life :/
Worse case scenario: you lie and give some rushed feed back based on what you can glean from the synopsis on the back. (Also happens more than it should.)
Even worse case scenario: it's the author of that book trying to be sneaky O_O (has happened once. Lucky I wasn't the one helping them. )
The sad truth is: we can't read everything :/ and that's not from lack of trying. In my store alone we carry 30,000 books. That means that, from the day I was born, I would have needed to read 3.5 books... A day. Every day. Not including the 500 or so new books published a day (that number has gone up dramatically with self publishing.)
Well... Frankly, that's a lot.
I do read a lot. I promise. Making my way through 5 books right now, one of which is a non-fiction. Beat that! (Here is a little cartoon of my pain)
If someone were to come in and say "can you recommend a book that's great for _______" I can normally ramble off 10-15 books that I have read. :) be proud. I know I am.
So yes... Don't think poorly if your bookseller has never heard of a book. Chances are it is just sitting in the pile next to their bed at home.