AdGooroo Estimates Top 25 Search Advertisers

AdGooroo regularly puts out some very unique and interesting data on the SEM space, and today's report is no different. The report has some very interesting data points on ad coverage, # of ads/page, # of advertisers and ads displayed per impression.

But what I found most interesting this time around was AdGooroo's list of who they deem to be the top 25 U.S. PPC advertisers by search engine (the estimate "is based on total number of recorded first-page ad impressions"). Advertisers in the top 25 list for Google, but not for Yahoo or MSN are:

Ask.com (one of G's top 3 distribution partners, so no surprise that they're doing G-sanctioned arbitrage so to speak)
Dell
DexKnows.com
Google (hmmm, does Google's marketing dept have to pay internally?, and lo & behold, Google's not on Yahoo or MSN's top 25 list)
Shopping.com (AdSense distribution partner, a la Ask.com. Arbitrage, baby!)
TripAdvisor (Part of Expedia, and you'd expect T.A. to be top 25 given that the measurement is based on ad impressions; T.A. is probably living in avg ad position 5-10, below the more transactional travel sites but high enough to feed Expedia a daily diet of warm leads)
WireFly.com - now that all the wireless companies are trying to compete with the iPhone, let the PPC marketing dollars fly. WireFly (formerly InPhonic) will do well, or die trying, as they did in 2007 when unsuccessful PPC & online marketing led to bankruptcy. I wonder what they'll do differently this time around?
Zappos - I've never bought shoes from them, but their Google Maps mashup is a must-have if you want to know just how god-awful America's taste in shoes is. [NOTE: if you want great shoes that will last 5+ years and get positive reviews from SEM & custom shoe officionado David Rodnitzky, Berluti in Paris is the place to go.]