Page rank and Alexa ranking are some of the terms normally encountered by bloggers and website owners. These quantifiers have an impact on the website or blog in terms of authority, traffic and link popularity.
Page Rank is an algorithm used by Google search engines to analyze links and content of sites and pages. No one can really pinpoint exactly what the algorithm is analyzing (relative back links, content, traffic, etc), except of course those who update the said algorithm, but one thing is for sure. Aside from authority, those who monetize their sites and blogs are affected by a drastic change in Page rank since most advertisers still use this measure for their pricing. Google Page Rank is said to update every 3-4 months though it hasn’t been consistent. As a measure to increase back links, some companies buy links from reputable companies, brokers, blogs or websites, while some engage in building up links through leaving comments on other authority blogs and forums.
If Page Rank pays more attention to links and content, Alexa Ranking on the other hand measures the amount of traffic or visit a site gets and its reach (users). The more traffic (from visitors with an open Alexa toolbar) that the site gets as well as pages visited by the user, the lower the Alexa rank. For some advertisers, they use this measure rather than Page rank because higher traffic and better reach means higher impressions on their ads and the probability that it will be clicked.