Yikes... probably too early to effectively compare...
Yahoo is paying a lot better than Google on comp ads at the moment, but I don't expect that to continue (I expect the market to level out...).
My CTR the past 2 days has been pretty bad with Yahoo, but before then it had been 40% higher as compared to Google (Google = X% , Yahoo = X% + X/40% )
Keep both as an option for the time being, give it 6 months, and see where the chips fall.
-Allan :gl: