Every week an employee from Location3 thinks of a search marketing question and quizzes everyone in the company via email. These quizzes started out as a way to brainstorm blog topics but have grown to become a way to educate all of our employees on the different services our company offers. Everything from social media and search engine optimization to pay per click and analytics. A few weeks ago, search engine optimization was the topic so the questioner found an interesting and rather thought-provoking question from SEOmoz.

Which of the following is the WORST criterion for estimating the value of a link to your page/site?

A. The popularity of the domain on which the page is hosted according to Alexa

B. The ranking of the linking page for its targeted keywords

C. The number and quality of other external links on the page

D. The PageRank of the page in the Google toolbar

E. The inclusion of the page in the indices of the major search engines

Apparently this one is a doozy because we only had one employee get the question correct. According the SEOmoz quiz, choice “A” is the worst indicator of the value of a link to your page.

Alexa traffic ranking is considered one of the worst indicators of a website’s popularity and importance. This is due to the fact that Alexa gathers most of its data from the traffic of people who download Alexa’s tool bar. According to Alexa, it “could not exist without the participation of the Alexa toolbar community. …by using the toolbar, each member is contributing valuable information about the web.” Statistically, the 10 million downloads of the toolbar would be an effective way of gathering data for larger and well-known types of sites (i.e., Google, Yahoo!, Facebook).

Many people who use the Alexa toolbar are going to be more knowledgeable about the web than those that have never heard of the toolbar before. Therefore, it is using a very specific and self-elected population to draw very general conclusions about internet traffic. Furthermore, webmasters can easily encourage their network and site visitors to download and use the toolbar to help their own site’s ranking.

When it comes to judging the importance of a site and the links coming from it, Google page rank seems to be a more common option chosen by SEOs, but many will argue that page rank is also inaccurate. What do you value as the BEST criteria for estimating the value of a link to your page or site?