Alexa Sparky Firefox plugin is a tool used for website's SEO analysis. It tells about Site's Traffic Stats, Search Analysis, Audience and other. You can login to amazon site and review your favorite site as well. Alexa Sparky is a Amazon product.
It helps me in seeing a website's worth, when I get while browsing net or by friend. This way you can understand at which place you are. If website owner/webmaster claim that their site is worth this or that then just look down to your browser's bottom right corner. If you are at very new site and it does not have any ranking then be careful of infection.
View from Bottom-Right of Firefox
Download Alexa Sparky for Firefox here.