Internal linking is extremely important when practicing SEO because it helps Google to determine which pages are important. However, trying to determine if the anchor text is just as crucial can be quite tricky. Shaun Anderson from Hobo Web tested out several pages that used internal linking with keywords as the anchor text. While these pages may be ranking, Google could just be reading the content on the page or it could just be because there are multiple links.
Shaun decided to add an internal link to one page using keywords as an anchor text. The target page did not contain keywords so really the only signal was the keyword used as the anchor text. A few days after the test was implemented, the page ranked for the intended term. When the keyword was removed, the page had dropped. Since that page did not have any relevance to the term (besides the link) the anchor text is the only reason why the page ranked.