Also, I should caveat this by saying that my children are precocious readers. My boys have been reading since they were two and my daughter reads more books in a week than I do. So titles did factor into these books in all cases.
8 yr old-- "I think it's a true story."
10 yr old-- "It's about the girl on the cover and there's someone she loves and something bad happens to him or her and she has to save their life."
10 yr old-- "Well, if it's about time travel, then it's where this girl meets someone when she goes back in time, but she can't marry him or her because she's from a different time."
10 yr old-- "It's about a girl who discovers a secret. Or maybe it's 13 reasons why we named our dog after this author."
5 yr old-- "Yeah, it's a book about the dog."
5 yr old-- "And she has a lot of lipstick"
10 yr old-- "It's about a girl who would do anything to be beautiful."
10 yr old-- "It's about someone who used to have a privileged life and now she lost everything."
10 yr old-- "Yeah, and it looks like it's a crush on a boy."
And finally, just for fun...