What is Nike's unique selling point?

Nike, one of the most powerful brands in the world, has a very strong slogan. Even if you take away the logo and the brand name, people will still think of Nike every time they see "Just Do It". However, it does not really convey their USP explicitly. Professional athletes from around the world use Nike even today and that's what Nike's unique selling proposition is. When you buy a Nike, you buy shoes that are made for professional athletes. Since many professional athletes use Nike, you should buy one too.