What is the use of Alexa search engine

Alexa's directory ranks its related links based on popularity, so if your website is popular or if you're listed in a major web directory chances are, your site will be well placed in Alexa.Alexa's toolbar was first released in September of 1997. Today, the toolbar is version 6.5, and features information about the web site being viewed, a list of related links, and a link to Alexa's information about that web site.

ALEXA is commonly used for viewing traffic to a certain site. also alexa rank can be used as site's popularity.

Why does the alexa search engine ranking show more people going to yahoo.com than does other keyword ranking systems?

I feel the alexa setup is more of a fun type tool for webmasters to brag about their lower number and feel better psychologically. It also does help give you an idea of a websites traffic and popularity. It really doesn't mean much but it is something every webmaster should have installed, as a lower number does look better!

its really important for seo work.

Alexa doesn't give accurate result. It considers only traffic. While google considers backlink. I think backlink is more important than traffic.

alexa search engine is just like other search engines but it consider traffics and alexa ranks to give u good SERP..its not that famous like alexa ranking..

Use of Alexa search engine is it give best result in the basis of traffic, how much your site is informative, how many unique visitor comes in a day.

Alexa statistics are woefully inadequate! its statistic is recorded every time a user with these toolbars installed visits a site their visit is logged with Alexa in an anonymous way.

Alexa provides rough estimates and in my case, i did not find it comparable to google and yahoo.