http://www.usmagazine.com/entertainment/news/gossip-girl-cast-ashley-olsen-rumer-willis-blair-serena-2015610

They were originally considered to play Blair and Serena, CW casting director David Rapaport tells Buzzfeed in a profile on how he helped build the CW network (http://www.buzzfeed.com/jarettwieselman/the-man-who-helped-build-the-cw#.hu8OEWNa).

http://www.people.com/article/rumer-willis-talks-awful-gossip-girl-audition

"You know, it was actually totally news to me," Willis said of this week’s revelation by CW casting director David Rapaport. "I felt like I did an awful audition back then. I was so young and it was, like, one of the first things I'd ever auditioned for."