Interesting items and some explanation of what it is over at Ephemera Society of the UK. And the US site. Vintage Depot Direct is full of vintage postcards.
Found elements, Ephemera Now, I love this very large die-cut advertising Clark's Thread from Ephemera Net. And this old paint chip example at 1800's Ephemera. Motel Postcards from Lileks. And also money from other nations.
I could not resist buying this roll of vintage yearbook school pictures, over 300 of them, from Vintage-Ephemera.com.