Well that may be true, but unbiased information is just not available in commercial settings (even the government "which solar panel is best" information is politically influenced, plus it doesn't even list correct pricing). I usually book hotels on kayak, but what hotels are listed there ?

The ones that pay 5% of the booking price to kayak.

Face it, without commercial incentives you'd never get accurate pricing, making finding the cheapest hotel VERY hard. Finding a 5% cheaper hotel costs me the better part of the day, and that will generally be worth far more than the 5% of the price that I might save (ie. 15-20 bucks). Also, sites like kayak may not get volume pricing, but they do seem to get lower prices than I can get myself.