Between the time you book a trip and the time you take it, there's a good chance that the hotel, rental car company or airline lowered the price. These websites (one of them just launched) watch your purchase and rebook you at a lower rate automatically, or alert you that you're entitled to an airline price drop voucher.
Surprisingly, once you book a hotel room there's a good chance that the same room and dates will go down in price between reservation and arrival, as I discovered quite by accident last year when booking a hotel stay in London. Needing to book an additional night's stay, I rechecked my reservation (made on Expedia.com) a week before my arrival and discovered that the daily rate had decreased by $75, saving me $750 on a 10-night booking.
Just launched, there's now a website that will do the price-check-and-refund work for you automatically, rebooking you at the lower rate, and checking for further drops up until the day of your arrival or until the rate becomes non-refundable (usually a day or two before arrival). There's no work on your part. Each time the rate goes down, Tingo.com sends you an email with a new booking number at the lower price. Key here is that another consumer doesn't have to book the same room category and dates at a lower rate for the refund to kick in, unlike Orbitz' "Price Assurance" program, which also refunds hotel price drops but requires another Orbitz customer to book the same room type, check in/out dates, number of guests, and restrictions in order to trigger a refund. (It's worth disclosing here that I'm the president of Airfarewatchdog.com, which is a subsidiary of Smarter Travel Media, which also operates Tingo.com.)
I recently booked a one-night stay in Washington using Tingo during beta and exactly a day later received an email that the price had gone down $22. Although the site is new, beta testing has shown that rate drops occur about 33 percent of the time with average savings of $36 on a two-night stay, although savings of over $500 per stay aren't unheard of. Unlike rental car site Autoslash car rental and airfare refund site Yapta, below, which work only with certain vendors, Tingo works with virtually every hotel group and thousands of independent properties, unless the consumer is booking a non-refundable rate (which, admittedly, are sometimes lower but can leave you stuck with a room you can't use when the meeting or wedding is canceled). There's no limit to the amount of the refund using Tingo, there are no claim forms to submit and the refund is made directly to your credit card.
Since its founding in 2006, Yapta.com has allowed consumers to enter their flight details on several airlines and receive an alert that the fare has gone down, making them eligible for a partial or full price drop refund voucher. The site only works with Alaska, American, AirTran (until it's fully merged with Southwest, which doesn't participate), Delta, Hawaiian, JetBlue, United, US Airways and Virgin America. (No foreign-based carriers participate.) And, of course, only Alaska and JetBlue (and for a few more months, Airtran) will give you back the entire amount of a fare drop refund, in the form of a voucher good for future travel up to a year from the original booking, with no fee.
The other airlines, if they refund at all, usually deduct $150 from the value of any voucher issued for a domestic fare, and up to $250 on an international fare, which often wipes out any savings. Even so, Yapta has helped saved consumers millions of dollars since its founding, although whether or not these flyers ever ended up applying their voucher savings on a future flight is anyone's guess, and it's always possible that revenue-hungry airlines will increase the "refund fee" at a future date, or eliminate price drop refunds entirely (after all, Saks Fifth Avenue doesn't refund the difference if you buy a suit in May and it goes on sale in June).
Orbitz' Price Assurance program issues cash refunds, not vouchers, if an airfare you booked goes down after you buy it, but again, another Orbitz customer needs to have booked the exact same flight numbers, flight times and dates for the refund (up to a maximum of $250) to kick in (read the full terms here).
Rental cars: Autoslash.com
Rental car rates fluctuate, too, and Autoslash.com will track your booking and rebook you automatically if the price goes down before you pick up the car. Not only that, but the site will apply any discount coupon codes you might be eligible for, further lowering the cost. There's no need to issue a refund since you usually haven't paid for the rental in the first place (although some companies now offer discounts for prepaid rentals).
Caveat: the site only works with Hertz, Thrifty, SIXT, Dollar, Advantage, Europcar, Payless, E-Z and Fox, so it's possible that one of these non-participants would have a lower rate even with a price drop on a car booked with the companies that play ball; so far, other companies (Avis, Enterprise, Budget, National, Alamo) have refused to participate. The company claims it has an 85 percent success rate in reducing the cost of its customers' rentals.