Magnus - Shazam for art
WikiArt - The Encyclopedia of Fine Art
Facebook Marketplace - Marketplace is a convenient destination on Facebook to discover, buy and sell items with people in your community.
ArtMajeur - +1 Million original artworks, Free Shipping Worldwide, Low prices guaranteed, 14 days return: buy all the art you love on Artmajeur!
Lancerlist - Find freelancers in your city
Saatchi Art - Online art platform for buying, selling and discovering art.