Google measures average time on site by first collecting each visitor’s exact time on a particular page. Imagine that a visitor lands on page 1 of your site. Google places a cookie, including a unique code for the visitor and a time stamp. When that visitor clicks through to page 2 of your site, Google again notes the time, and then subtracts the time that the visitor arrived at page 2 from the time that the visitor arrived at page 1. Google then averages each and every page’s time spent to get the average time each visitor spends on the site.
The term “organic” refers to something having the characteristics of an organism. Although black hat SEO methods may boost a website’s search engine page rank in the short term, these methods could also get the site banned from the search engines altogether. However, it is more likely that readers will recognize the low quality of sites employing black hat SEO at the expense of the reader experience, which will reduce the site’s traffic and page rank over time.
The term “organic traffic” is used for referring to the visitors that land on your website as a result of unpaid (“organic”) search results. Organic traffic is the opposite of paid traffic, which defines the visits generated by paid ads. Visitors who are considered organic find your website after using a search engine like Google or Bing, so they are not “referred” by any other website.