According to Quantcast, InsiderPages has a lot more traffic than Yelp (3.3 million uniques to 2.6 million uniques).

I’m dubious of this since InsiderPages has not been updated in a long while and has been actually down today (when i tried to check out the site).

Compete.com tells a different story w/ Yelp about triple the traffic of InsiderPages:

But Compete also shows InsiderPages.com up over 100% in the last year (whereas Quantcast shows it down from last year). Just shows that web statistics, even of high trafficked sites, is very hard to judge. and even their relative position is very hard to measure. Companies like ComScore, Quantcast, Alexa, and Compete are part science, part art. i’m still a big fan of what they are doing (it is quite hard … but very important), but it is a note of caution when trying to judge a site’s popularity.