Feb
Suicide by SLURP
Yahoo Indexes Adwords Tracking URLs
One of our SEO’s here pointed out this odd SERP from Yahoo this afternoon.
Take a look at results 1 & 3:
If you look at the tracking variables, these are clearly Adwords ads that have been indexed by Yahoo. Not only are they indexed, but they rank as #1 and #3 for this particular query. So, one would tend think about how this could screw up your analytics. Basically, if you were utilizing an java-based analytics program any conversion that came through this url would be attributed to your Adwords PPC campaign, at least on the surface. This would result in a couple things:
1. Your ROI for Adwords would be falsely inflated.
2. If it happened on a large enough scale for a big advertiser, you can see the potential ramifications.
3. Yahoo loses credit for any traffic it sends you organically, and eventually makes itself less relevant.
4. Google share price increases 
Update: Further discussion on this topic from SEORoundtable