Here's a puzzlement: Can every travel website really offer the lowest price for your hotel or airfare? That's what many guarantee. They can do that partly because rates and fares don't differ much from site to site.

The reason for this lies with pricing parity agreements, in which online travel agencies such as Travelocity and Orbitz agree not to undercut the website rates of travel suppliers such as Marriott and Starwood. So all stand a good chance of being right when they say they have the lowest or best price because they have agreed on the same offer. And on the rare occasion a price is higher, the difference is usually not great enough to justify the time you would spend jumping through hoops to claim the guarantee.

Nonetheless, Expedia last month announced a low-price guarantee for travel purchased on its website, joining the legions of other such online providers offering them, as well as many airlines and hotel chains.

Webster's defines "guarantee" as a "pledge to replace something if it is not as specified." But the long list of what these so-called guarantees don't cover is much more comprehensive than what they actually do.

Get the full story at the Los Angeles Times