Yesterday, I spent a fabulous half hour or so rummaging in a shed at the back of a furnishing store - with their permission obviously! There were shelves and boxes full of old sample books for sale. When it comes to fabric, I know instantly what I like and also, more importantly, what I will use a particular fabric for. Some samples are too small to be of use to me and other fabric have a design that is too big, so they get discarded as well.
The best bit but also the hardest bit is taking the books apart. You can simply cut the fabric out but you lose a few centimetres doing that. If the samples are small to start with, you don't really want to lose any more that you have to. I prefer to rip the binding apart and gradually rip the fabrics out. Most are stuck in with really strong glue, so it's not easy. I ended up with a large stack of gorgeous fabrics though which will last me a while, so it was definitely worth the effort.