Another factor that plays a role in a company's SEO campaign is the popularity of its website. Popular sites are generally seen as authority websites because they have a large number of visitors. The popularity of a site will translate into a high search engine ranking. This is because the more popular a website is, the more likely people are to visit it, and as a result, the site will be indexed more often. If the website receives a lot of traffic, there is a greater chance that more people will click on the advertisements on the site, which will drive up the total amount of money earned through the advertisements. As a result of this, SEO companies often charge their clients a reasonable fee for helping them achieve a high search engine ranking.