Yep, I'm fully aware that its the same two or three companies that own most of the hotel booking sites, I never thought or suggested otherwise and they cleverly "appear" to play each site off against the other, however that still doesn't stop you sometimes winning that game ( or at least not OVER paying) by checking them all against each other ( and not via one of the comparison sites as they too are ALSO owned by the very same companies half the time.

Re your "hotels that list with them are not allowed under their agreement to offer prices via their own Web sites to the general public that undercut the price they offer the consolidators" - yep, I believe thats exactly what I said too so you're bang on there as well. And likewise re your "It's always possible that a hotel will offer a better price if contacted directly, either via email or walk-in, but not otherwise".