It's a partner deal with Canstock. You get commission on print and product sales or a 25c subscription sale for the 10x8 free prints that FreeArt offers. Here is the thread from when it was first announced
http://www.microstockgroup.com/canstockphoto-com/exciting-announcement/ . Anyone that has no intention of selling direct through an art site like FineArt America may welcome the extra (potential) sales. Otherwise you can ask to be opted out of the deal (I did and they did it promptly). Regards, David.