This tool allows one to analyse changes which have occurred across the category over a period of time - actually way back to the start of the internet revolution.
This tool allows you to triangulate traffic graphs from Alexa, Compete, and Quantcast of any website you're browsing. Very handy.
This is a free and easy analytics tool that allows one to track a website more easily and effectively.
comScore's Brand Metrix measures the impact of online advertising on a brand’s level of awareness and the attitudes and perceptions towards a brand. Also check out it's other tools.
Read more about digital tools on my A to Z list ; Click here