Hello all!  This may seem like a dumb question but I am new to this and was curious about something.  If you are looking at someone's wishlist and see a book that they want and I have it posted on my bookshelf wouldn't it automatically notify that person that this book was posted?  Or do you have to PM the person and let them know that you have it posted and see if they are still interested in it?

Your copy is likely a different ISBN or possibly even a different binding than the one they have wishlisted.   If it's the same binding that they want (hardcover or paperback), they might not have every possible ISBN on their wishlist.  

But if yours was the identical ISBN that they had wishlisted, then yes, they would have gotten an automatic notification.   So there must be *some* difference between your copy & the one they have wishlisted.   

Most of the time, the system sends out notices that a "similar" book has been posted - but some folks turn those notices off, as they can get bothersome in some cases.   (For example, if I'm wishing for a hardcover edition of a book, I'll get a "similar to..." notice every time a paperback is posted & for a popular title, that can amount to multiple notices daily - so I turn them off sometimes)