Despite contracts between hotel chains and online travel agencies that mandate all distributors get the same room rates as displayed on the hotels’ own web

Source: skift.com

Once travelers realize that the room rate on Expedia may be significantly lower than the one offered on Booking.com, or vice versa, then there would be all the more reason to use a hotel metasearch site to compare all of the available prices at once rather than start the search process on an online travel agency site or even the hotels’ own websites.