How do you realise if sneakers are fake or not on websites that sell

[simone]

There are hundreds of websites that sell shoes, and all of them appear to be selling "authentic".I've found an article that explains how these things work and how to be aware of it, and lists some websites :

http://www.hoopsvibe.com/web_reviews/fake_or_authentic_sneakers_pick_the_right_website-ar31713.html