Goodreads Librarians Group discussion

I wanted to add on the page number to the edition of The Agony and the Ecstasy I chose to use on My Books as it has the same cover that I have. However upon reading the information about it, I discovered that the edition was a rerelease, although the publisher and date were the same as the book I had. The size and weight were different as well.
Is this a case where the most popular version is the edition used?
If this is the case, I take it that it would be best to leave the page # at zero..
Thank you. I am a new librarian.