Ranking in Alexa is irrelevant, as the number of real world people who use Alexa for search is practically non existent. Focus on Search Properties people actually use... Google, Yahoo, Bing and to a lesser extent Ask
This is a ranking system set by alexa.com (a subsidiary of amazon.com) that basically audits and makes public the frequency of visits on various Web sites. The algorithm according to which Alexa traffic ranking is calculated, is simple. It is based on the amount of traffic recorded from users that have the Alexa toolbar installed over a period of three months.
Alexa Rank is more of your visitors are getting alerted of the Alexa Ranking. The alexa improved due to your traffic increase, not the opposite way. And alexa ranking can be boost by using tools, it is not accurate enough. Alexa Ranking provides you an immediate view of you and your competitors’ performance comparison.