Search engine optimizing is always changing,which you learn today will not be so useful after a year.It get updated as per the need.Again we refine our AdSense website and try to optimize it.But there are some factor for which search engine always give importance. 1). Inbound links (back link) 2). Site Authority. 3). Keyword in html page title. 4). Content of website. 5). Domain age. 6). Look and feel of web page. If you concentrate on above factors.There is more chance to get your web page visible.