PPC is a type of sponsored online advertising that is used on a wide range of websites, including search engines, where the advertiser only pays if a web user clicks on their ad. Hence the title, ‘pay per click.’
When a search engine crawler comes to your site, it will look for a special file on your site. That file is called robots.txt and it tells the search engine spider, which Web pages of your site should be indexed and which Web pages should be ignored.
The robots.txt file is a simple text file...