Working the customer service desk at a public library gives me the opportunity to interact with readers of all ages. I must admit it gives me a thrill to see young readers borrowing the same books that I loved as a child (and believe me, that was a few years ago). Beverly Cleary's books really bring back memories, and I think anyone who has a younger sister will enjoy the Ramona series, even as an adult.
And then there are the adult readers who come to the desk in a panic stating, "I've finished reading all of the books written by my favorite authors and I need someone new, now!" I can certainly sympathize. There is nothing quite as horrifying as a reading drought.
Since I read a lot of fiction, especially mystery/suspense and sci-fi/horror, I often make suggestions of authors who write in those genres. I get a feel for who might be interested in lightweight or humorous mysteries, and who might be more into the darker, hardcore private eye type stories.
There are also many different sub-genres within sci-fi/horror, so if a customer says they have been reading Stephen King, I might suggest Dean Koontz or F Paul Wilson. But, if someone asks me for a new author of romantic vampire novels, they are out of luck. Hey, vampires are supposed to be evil and bloodthirsty!
Feedback on these recommendations is mixed. Sometimes a customer lets me know that an author I suggested didn't quite meet their expectations, but I know I've been successful when a familiar face pops up at the desk and asks, "What are you reading?"