I wondered the same thing. I have three 3-ring binders I used for my smash books up to 2011. I'm going to get an actual brand-name Smash Book for 2012. I mostly use them for ephemera. I scan ticket stubs and such for digital scrapbooking and get the layouts printed in books, but I don't want to get rid of the actual notes and pieces from my "moments."
I've used about 30 sheets each in my books. I use large, really large, rubber bands with cute smiley clips as bands for the books.