Alexa Ranking is not accurate, easily manipulable

Alexa is one of the leading Web statistics and comparison site in the Internet. It is accurate for the sites with High traffic but not for smaller or medium traffic sites. It can be easily influenced by a single person's use.
Alexa Ranking is taken as reference in Website worth, Website value calculation, Website ranking by Many other sites around the internet. But..

How is Alexa Ranking made? What is it Based on?
Alexa ranking system is based on data it collects from the millions of alexa tool bar users around the internet.
It calculated ranking based on Number of visitors using alexa toolbar, number of pageviews from them and time on site.
So if your website is getting a 10,000visitors but  only 10-20 use alexa toolbar you are likely to lag behind in the ranking to a Blog that receives 200 visitors per day with 50-60 viewers using alexa toolbar.
So I think it's rather irrelevant system.
http://merabheja.com/alexa-ranking-methodexplained/

Still its the reference of Internet Market, as Alexa ranking determines you ad space value and text link values.Advertisement ie Market.

What kind of sites have better Alexa Ranking?

• Alexa ranking is accurate enough for Sites getting High traffic. Like Google, facebook, Youtube,twitter,etc which is of common use to all.
• Blogs that provide blogging tips and tricks will have better ranking benefits as most visitors are bloggers and they usually have Alexa tool bar installed.
• Similarly sites where people spend more time like Blogger,Wordpress, Paypal,Social sites, Video sites will tend to have better ranking.

Other sites will lose the ranking of Genuine visitors if Alexa can't measure it.


Example:-

When my website ( not this one , another dotcom site) was under construction , I used Firefox with alexa tool bar. I spend a lot of hours in the site. when I was getting not more than 50 visitors per day, I was ranked within top 500 thousand in alexa. Soon with a month my rank jumped to 200K and less than that.

I reviewed my rank in Alexa and found my average Pageviews aroung 10 that's unusual for my site and time on site was 14 minutes that was totally out of the track. I think my use of alexa toolbar singly Influenced the rank. Now Imagine how much you can improve your rank if you have 50 computers with alexa toolbar under your control.

Now, when I'm getting 30,000 visitors per day and 45K + pageviews my alexa ranking is dropping constantly from 200K to 300K and to 400K+ and now heading towards 500K.
The cause I found was I am using Google Chrome to surf the net which cannot intergrate Any toolbars.So if experiment once again, today I'm leaving mysite online on Firefox with Alexa toolbar, will be doing this for a week.

I know my rank will jump back.

So I prefer not to say Alexa Traffic ranking.