Why my $_POST is empty?

I have no time and too tired to struggle with this, so I decided to ask here: I've created the file my.php which contains only:

<?php var_dump( $_POST ); ?>

And then I open the file using browser like this:

http://ift.tt/1Fib0OU

And in the browser I have array(0) { } as a response.

Question: What could I possibly done wrong??

Thanks!