This is what I wondered for a long time. How does alexa.com manage to collect traffic information of all the sites in the world? They don't have their scripts installed in any of those websites. So how is this data collection possible?
The calculate the visits using their toolbar. In simple words, they count the visits just from users that have Alexa toolbar installed in their browser.
There are different sources of traffic information alexa collects from. most prominent of them is Alexa tool bar information. Have you noted, on installation they ask about the age, location etc. this information is used to calculate the demographics of your website. That is the reason alexa is not that apt. further they also have other resources, SEs, research data which all pour into their rank calculations. cheers Josh
This is what I wanted to know more accurately, how do they peek on search data? What about traffics that went directly to the website by typing into the browser? Very small portion of the internet users installed that toolbar. I think it's well under 1% . I think they might take help from ICANN. Or maybe from hosting services (doesn't sound practical). Any body knows the mystery. Their data might not be 100% accurate but quit good I must say.
Alexa isn't entirely accurate, because it relies on statistical sampling that isn't random. Alexa achieves its ranking system by counting how many pages were visited by people who have downloaded their toolbar. And that group of people is anything but random: they tend to be webmasters, internet marketers, and other market-minded people. And technical people tend to completely turn up their noses at Alexa rankings, because installing a toolbar that "spies" on their surfing habits makes them upset, even though Alexa only collects aggregate information (nothing that should be linked back to an individual). When you need to quickly find unbiased, third-party information about any site on the internet, try the easy-to-use tools that you’ll find at Alexa.com. While its not perfect, it’s a quick way to catch a small snapshot of internet marketing information. For example, if you're considering advertising with a site, check their ranking number to get an idea of how effective they might be at delivering high quality traffic to your website.
Yes you are true, But its not 1% its more than that. The data is inaccurate due to the tool bar idea. Also they get data inputs from other sources too. In addition the accuracy depends on your niche, for example most of the webmaster or webdesign websites is for the users who mostly have alexa installed and other niches might not. cheers Josh