Copyrights of celebrity photos

Hello Everyone,

I know no one has a right to use celebrity photos taken by someone else for commercial purpose.
But there are lots of website that make money using the celebrity photos such as www.coolspotters.com, http://www.celebritystyleguide.com
or www.stylelist.com.
I was wondering how they can use the photos legally.
Do they buy them from some companies opperated by someone?
To think like this, the photos on their website are A LOT to pay for all of them.
I am thinking to launch these kind of business in South Korea.
welcome any kinds of advice for me.

thank you
soon park