Many people simply go on-line, check out a couple of web sites, see prices are similar ... and throw their money away.
It's understandable if, in VietNam, you don't know where to buy travel since it always appears every hotel and xe om driver sells tickets - just look at the trolls who pop-up here offering their services.
In VietNam there are extremely few 'Travel Agents' as we know them, they are telephone order placers doing little you couldn't do yourself. An IATA approved Travel Agent can actually issue tickets, from a Res System, accept payment and get tickets on credit.
In fact the best source for cross-border travel is often the Agency who flew you here to VietNam ... unless you booked on-line.
On-Line Reservation Companies
The incestuous relationships in the retail travel business would put a multiple bigamist to shame. They cost users big time, and they get second class service.
The four biggie on-line companies, along with their siblings are:
EXPEDIA INC. which owns Expedia.com, Hotels.com, Venere.com, Hotwire.com. Hotwire.com which owns Carrentals.com and Travel-ticker.com and TripAdvisor.com. Sweet, innocent, complaining TripAdvisor.com owns subsidiaries CruiseCritic.com, BookingBuddy.com, SmarterTravel.com, SeatGuru.com, AirfareWatchdog.com and IndependentTraveler.com. But there's even more. Expedia's huge in China with the ownership of eLong.com. And we mustn't forget Expedia also owns Egencia, Classic Vacations, Expedia Cruise Ship Centers as well asExpedia Local Expert Destination Services;
ORBITZ WORLDWIDE which owns Orbitz.com, CheapTickets.com and RatestoGo.com;
SABRE HOLDINGS which owns Travelocity.com, IgoUgo.com, LastMinute.com and the large Sabre reservations system used by the travel industry. Travelocity also is behind the search on Yahoo! Travel;
PRICELINE.COM which owns Priceline.com, Travelweb.com and Lowestfare.com.
And that TravelAdvisor had the affrontary to complain to the EU that Google was 'unfair competition'!
SABRE HOLDINGS, formerly owned by American Airlines, even screws it's own customers. Sabre is a travel agent GDS, those computers that travel agents use, and it is therefore selling against the travel agent through their retail facing web sites.
Cookies
By the way, about cookies. When you check prices of any of these groups of companies, the cookie contents are used by associate companies to ensure that price quotes are similar!
So much for competition!
To test this, go and check out prices by the companies owned by TripAdvisor, using the same propert(y)(ies) as a reference. Then repeat the exercise BUT DELETE the appropriate web site cookies BEFORE loading a new site.
Wonder of wonders, price differentials begin to show ... ah the magical cookie.
Privacy
Then think of the personal data you give these outfits. The consumer hasn't a hope in hell of privacy.
And dear old Uncle Sam looooves sucking the data out of those res systems, it has a great tracking system with almost 100% certainty of identification.
Buying tickets from an airline directly often skips a major res system computer. Amadeus computers are in Europe and under different legal jurisdiction.
Solution
USE YOUR HOME TRAVEL AGENT for the best service and protection.
Disclosure: I am not employed by any of these companies or competitors, nor do I have any interest in travel agencies, I am just a consumer who travels frequently.