It's like asking what makes any site great? They all have their nuances and differences. I looked at several photo sites and decided that 2 would be plenty. I chose this site (photographyreview.com) as it has a more disiplined and still knowledgeable userbase and choose flickr for it's easy to use interface and popularity.Originally Posted by Kokopeli
I don't think it detracts from PR at all to have other avenues to showcase you photos. Infact like PJ said, we can use Flickr to promote PR.