Revolution Health's Traffic - How to Play the Traffic Game

There was a comment on my earlier post on Revolution Health raising a good point - viz that I should check different traffic sources, and not just quote Quantcast. 

Quantcast, alexa, compete, comScore, hitwise - they all have different methodologies, and generally have different measurements for sites, even the big ones.  comScore is the one most advertising agencies prefer - but if you use comScore, be aware of what you're seeing. 

As an example, Revolution Health in comScore shows up as the third largest Health site;  this is because there are sites such as Drugstore.com, Daily Strength, and SparkPeople (which also runs SparkRecipes and SparkTeens), with a total of about 5.4 MM unique visitors, that assign their traffic over to Revolution Health.  Revolution Health represents these sites in ad deals, and in exchange gets to report their traffic in its "network". 

Revolution  Health also bought a few sites - CarePages in April 2007, and HealthTalk in December 2007.  It of course gets to report these sites under its traffic in comScore, and shows bump ups in traffic as a result of these acquisitions. 

If I were to take an impartial stand, I would (a) definitely remove 'ad representation' sites when reporting a site's traffic, and (b) put an asterisk next to traffic bumps due to acquisitions... but still include them.

Here is my take on comScore info for Revolution Health's traffic (leaving out smaller and sub-sites that don't contribute enough).  These are estimated numbers, of course!