Tracking other websites´ users (Analytics)

Question

I was wondering if there was any (legal) way to track websites analytics of any random site.

What I mean is simple, is there a way to actually know how many people enter Google a month?

I read around and found that Alexa extrapolates data from users with their toolbar and some cookies, im not interested in that, I mean a true measurement.

Where would you have to start if you wanted to write something like this?

I guess this is no possible but I can´t really understand why, are there any illegal ways of doing this?

Thank you very much!

Juan

Answer 1

I read around and found that Alexa extrapolates data from users with their toolbar and some cookies, im not interested in that, I mean a true measurement.

Nope, there is no way to do that. That's why Alexa needs to rely on extrapolation.

You'll have to rely on what the sites tell you.

Some commercial sites use services like Nielsen that keep an "official" visitor count on whose basis advertising prices are calculated, but this is not the rule.