Here is an interesting survey by BIG research. By their studies, MSN has the largest influence on consumers for vehicle purchase decisions.
As many dealers focus efforts into buying keywords on Google and Yahoo, MSN is about to introduce their own keyword purchasing/bidding program. "MSN adCenter". I’ve been closely working with Chad at AutoOptimize getting my current dealer set up for the new MSN adCenter program. It will be interesting to see if our visitors from MSN have a higher CTR and conversion ratio then our Yahoo or Google traffic.
I’ll keep you posted!