If I've scrapped someone I'm not in touch with anymore, the page stays in the books.
If I have extra photos I didn't use, I"m not inclined to keep them. After I scrap a page I either give the overflow of photos to other people in them, if they are are family I send them to my mother and if no one would want them I toss them out.
Still, I have a huge cardboard box of photos I need to do something with. My kids aren't going to want them so I need to sort out who migh actually want some of them and get rid of the rest.
Any photos that are any good are in my scrapbooks.