What value does a First Edition Book have over copies?

I have often been puzzled by the effort and trouble collectors go to to purchase first edition copies of books.  I'm not talking about some very rare copy of the Magna Carter or such, but old books in general of which there have been many editions, and copies of which are still available in second hand book shops. After all the contents of most books, we would call literature remain the same no matter what edition you may have in your hand. The logical conclusion to such endeavors is the need for prestige by such purchasers.

 Given the ability of technology to reproduce faultless copies of just about anything, we need to question what is it in the human physic that drives people to collect first editions. Personally I have always felt that the value of any book is the content. Likewise a musical score has no value until someone brings the music to life. The false value that society bestows on such items will always remain a mystery to me. This not to say I put no valve on one off objects such as painting, but simply objects that may be reproduced infinitely.