That is only fun because they already cataloged them for you. They made a little collection "used books for sale" with just the right size for you to enjoy browsing through. Now imagine you run into a barn full of books, a couple of containers outside, unsorted, all labeled "used books for sale" and no way to tell which were there last week and which weren't. At best you can visit 1% of the books this week, and next week the same 1%, or maybe another. That's what the issue is here.
Most people do not enjoy that more then once or twice.