1. Because I like to be able to let people know about my reading tastes - Giving a hyperlink to my bookshelf from my profiles on Myspace.com etc. gives this website more publicity, gives people a better insight into what I am into and gives the Authors free publicity.
2. Before Bookcrossing, I used to hoard books, like some dragon with a pile of gold - it didn't matter that I would probably never read a particular book ever again (with several thousand books, simply re-reading ones I already had would take several years non stop!) Now, I release books and have a great feelgood factor all day, making the world a library, one book at a time!
3. Being able to pass books on, but not neccessary losing contact with them, now means that I am now more willing to buy books that I would not have been willing to before - either because they are not my cup of tea or because I already had a copy at home - I am now buying a lot of books at car boot sales and charity shops with the intention of passing them on at some stage - my local bookcrossing group has benefited greatly in the last 3 months that I have been an active member!
4. Registering books and then taking them to Bookcrossing meetups, gives me the opportunity to rave on about a book or Author to other readers - this gives the Book / Author more free publicity. People are more willing to experiment with new things if they have had a personal recomendation! Bookcrossing should be on every Authors lips as a very positive experience!
5. Books have a natural lifecycle, everytime we read one, it gets a little more used, a little more battered. It enriches everyone who it passes though at a cost to itself - but some of those people may go out and buy a new copy to keep or pass on - every book will one day get to the point where it's pages are falling out, its spine will disintergrate, the cover will get ripped and the words will fade. Books may last longer on the shelf but enjoy themselves more being free and interacting with their readers!
6. I love wild releasing, not knowing into who's hands my book will pass next, maybe it will get picked up by someone and make their day (gifts are always nice!), maybe it will encurage that person to read other books by that Author / Subject, Maybe even finding itself in some far off distant land.....
7. Most books registered with Bookcrossing.com have only a few copies available - no impact on their Authors except publicity! the few Books which have hundreds of copies out there are the ones who are getting bought in their tens of thousands - so they are a drop in the ocean for the Author!
8. Bookcrossing changes lives for the better - and that is something you can't put a price on!