Increase the Alexa Rank
 

Why the Alexa rank suddenly increased?

i think the rank is based on traffic and backllinks, so any change in it, change the rank.

To be honest if your Alexa rank has suddenly increased probably due to low traffic on your site. If you want to decrease your Alexa rank, then you have to register with Alexa. I no longer pay attention to Alexa just promotes your site on social networking sites.