As more Web pages link to Discovery's Planet Earth page, the Discovery page's rank increases. When Discovery's page ranks higher than other pages, it shows up at the top of the Google search results page.
Because Google looks at links to a Web page as a vote, it's not easy to cheat the system. The best way to make sure your Web page is high up on Google's search results is to provide great content so that people will link back to your page. The more links your page gets, the higher its PageRank score will be. If you attract the attention of sites with a high PageRank score, your score will grow faster.
Google initiated an experiment with its search engine in 2008. For the first time, Google is allowing a group of beta testers to change the ranking order of search results. In this experiment, beta testers can promote or demote search results and tailor their search experience so that it's more personally relevant. Google executives say there's no guarantee that the company will ever implement this feature into the search engine globally.
Google offers many different kinds of services in addition to chat. In the next section, we'll see how some of them work.