Most travel websites, especially those presenting deals and allowing comparison of different packages, show the price per traveler. Same case for ads on Internet and billboards in cities.
When I want to dig further into a deal, I enter the number of travelers which is 2 by default... as I do not have a companion, I replace the value by 1, causing a price update which make that deal not so much interesting after all. Anyway, this is logical since the hotel room price is no more shared.
Nearly all situation stipulate that price is on a basis of "2 people sharing a double room". When planning solo travel, comparison is difficult.
Why is it the standard to assume that people often travel in pair? Is there any efficient way to compare travel offers for solo travelers? The question also applies for cruise lines.