For travelers willing to trade certainty for savings, Priceline, Hotwire and a new site called GetGoing are taking some of the mystery out of the opaque booking process.

GetGoing.com, which was officially introduced March 6, offers a twist on the blind-booking model popularized by Priceline, where you don’t find out all the details of your itinerary until after you book. Instead of bidding, you choose two places you would like to visit (say, Miami and Los Angeles), select your travel dates and flights, then enter your credit card details. GetGoing randomly chooses one of the two trips and books your ticket, which you can’t change or cancel.

The company aims to help airlines fill empty seats, which are scarce on some routes but still average nearly 20 percent of the tickets a carrier could sell. GetGoing promises savings of up to 40 percent off published airfares, but the coin flip reassures the airlines that they are giving these discounts to leisure travelers, not business travelers who would pay a higher price because they have to fly.

“What’s really key to the airlines is discounting seats to the right people,” said Alek Vernitsky, GetGoing’s chief executive and one of its founders. “By asking people to select two places they want to go and flipping a coin, we are communicating to the airline we just found a discretionary customer.”

Here is more information about how GetGoing works, and how it compares with Priceline and Hotwire, both of which have added features to make opaque booking less of a gamble.

GetGoing

What’s new: The coin-flip booking model. So far, GetGoing works with more than 10 airlines, offering flights to thousands of destinations in more than 50 countries. You can select two destinations in the same or different countries (or states), as long as they are at least 50 miles apart. Unlike Priceline, GetGoing lets you limit the options to nonstop flights, but you will generally save more if you accept a connection. Savings range from 20 to 40 percent off the lowest published fare, Vernitsky said, depending on the route and how desperate the carrier is to fill seats; you see the full price before you commit. Although you don’t find out the name of the airline until after you book, GetGoing displays your departure and arrival times as a half-hour window — e.g. “takeoff 5 to 5:30 p.m.” With Priceline’s name-your-own-price option, all you know before booking is that your flight will depart between 6 a.m. and 10 p.m. and might include a connection — too much uncertainty for some travelers.

Cool tools: To prove you’re getting a deal, GetGoing posts links to other booking sites like Kayak next to its prices, so you can check what the competition is charging (click the blue “I” button, which is not especially obvious). If you don’t have a destination in mind, you can search for places that fit a particular category, like “beaches and sun” or “adventure and outdoors.” If you log in with your Facebook account, GetGoing will tell you which of your friends have been to the destination you’re considering, making it easy to seek advice.

Wish list: GetGoing doesn’t offer hotel deals but plans to add them in the next couple of months. It also hopes to persuade more airlines to participate, which would expand the number of its destinations and flight options. A flexible date search would help to avoid separate searches to find the cheapest weekend to travel.

Priceline

What’s new: To entice customers who were put off by its name-your-own-price bidding model, Priceline created a new hotel booking option called Express Deals last summer. You still don’t find out the hotel’s name until after you book, but Priceline displays the room rate so you don’t have to bid. With Express Deals, you will see a list of amenities the hotel offers (like a pool, fitness center, free Internet access or free breakfast), and some hotels let you select a bed type (for instance, one king or two doubles). Brian Ek, Priceline’s spokesman, said Express Deals have discounts up to 40 percent off the hotel’s published rates, versus up to 60 percent off with the bidding option. On the airline front, Priceline now sells one-way tickets and displays recent winning bids on a particular route to help guide bidding strategy.

Cool tools: Priceline’s mobile apps have given procrastinators a reason to gloat. “The amount of inventory and the discounts we offer will get a little bit better toward the last minute,” Ek said, noting that customers are increasingly using smartphones and tablets for late bookings. Priceline’s iPad app is scheduled for a new release this summer but currently offers a map view that lets you tap on a zone in a particular city to see recent winning bids for that area. For car rentals, Ek said the savings also tend to be better (up to 40 percent off) for last-minute bookings.

Wish list: The option to choose only nonstop flights when you’re bidding, and the ability to select a narrower departure or arrival window. “I don’t even give bidding strategies for airline tickets anymore,” said Sheryl Mexic, the founder of the advice site BiddingForTravel.com. “Your schedule is totally out of your control.” For travelers who refuse to fly Spirit because of its high fees (even for carry-on bags), an option to exclude that carrier from the bidding results would be welcome.

Hotwire

What’s new: With Hotwire’s Hot Rate hotels, you see the price and amenities offered by a particular property (including whether there is a pool, fitness center, free Internet or parking), but you don’t know the name until after you book. Clem Bason, president of the Hotwire Group, said the company recently began indicating whether Hot Rate hotels in Las Vegas have a casino (or don’t); for some cities, Hotwire notes whether a hotel is pet-friendly. The site’s maps are also getting more detailed, Bason said, to help travelers choose the right zone. For instance, a bubble over the Magnificent Mile and River North area in Chicago describes that zone as a “shopping thoroughfare with blues clubs, art galleries and design studios.”

Cool tools: Like Priceline, Hotwire has been working on its mobile apps, offering better deals to last-minute bookers — up to 40 percent off the hotel’s lowest published rates, versus 20 percent if you book more than two weeks in advance. “As you get closer and closer to midnight on the day of check-in, the hotelier increasingly has incentive to cut that price,” Bason said. “In some big cities, we see prices changing from 9 a.m. to noon to 3 p.m.”

Wish list: A narrower travel window for Hotwire’s Hot Rate airfares, which are for flights that depart sometime from 6 a.m. to 10 p.m. on a “major airline” and might include one stop. You can’t limit the options to nonstop flights or exclude certain carriers.

Other sites

Other sites that embrace the opaque booking model include Travelocity’s Top Secret Hotels, Quikbook’s Secret Sale Hotels (mostly, boutique hotels in major cities) and Expedia’s Unpublished Rate Hotels (which might overlap with offerings from Expedia’s partner, Hotwire).