Hello All, I have a site which I use black hat technique to rank, at the beginning it rank well but it dropped later...I do not get any notice from google. I keep doing some white hat technique and it rank again....but there is wired thing that when I search my domain as example.com in google.com.kr, it do not show my site, but when I add www in as www. example.com, it show my site again....but when I use google.com, both of these two ways will show my site, is there anyone can tell me what happen on my site? example.com is different from www.example.com??