Here's a suggestion that could save readers lots of time (in terms of research and confusion) and money (in the case of duplicate purchases):

Include alternate titles.

Sometimes books are re-released with new titles -- very often, books first released in, say, the UK, are given new titles in the US. Amazon comments frequently reveal the frustrations of readers who have bought a new title only to discover they already own the book under another title. Author Sophie Hannah is one example -- three or four books with double titles -- and it seems that the titles that appear on FictFact are the original UK titles....confusing for this US reader!