As for the impact of the Internet on travel suppliers, a typical case is that of Sanjiv Patel, who owns and operates the Red Carpet Inn in Albany. Like many of the 240 franchisees in the Hospitality International chain, it is a modest hotel, with rates typically $50 to $55 a night. Before this year, Mr. Patel said the franchise didn't have the ability to accept reservations online, and lost considerable business to Marriott, Fairfield Inn and other competitors.

When the company started offering Internet reservations in January, through middlemen, the impact was immediate: the hotel booked 25 percent more rooms over the previous year's level. This was a particularly meaningful number for Albany, Mr. Patel said, because competition there is high and occupancy rates hover around 73 percent; the national average is about 63 percent.

There was, however, a catch. When consumers book with the chain's hotels online, Mr. Patel said, they are often offered discounted rates usually given only to members of AAA or AARP, so the hotel gets 10 percent less on the room price.

...."Used to be, airlines differentiated themselves with service, but technology will now become the big differentiator," Mr. Harteveldt said. "Airlines and other sites will offer many more online options, like flight alerts, trip reminders."

Perhaps more important, he said, consumers will probably find a larger number of Internet bargains in the future, as suppliers encourage customers to buy online. "Fares that used to be $20 cheaper online from the same carrier for the same route will be $30 or $40 less," he said. "Companies will charge less per seat, or per room night, or per day for a car, because the consumer is using a less expensive sales channel."

Perhaps no group has been affected by the Internet more profoundly than travel agents. Seven years ago, travel agents sold $73 billion worth of airline tickets, according to the American Society of Travel Agents. This year, they will sell $60 to $65 billion, while online travel agencies like Expedia, Travelocity and others will sell between $15 and $20 billion.

Agents who had eked out a living by selling airline tickets — as opposed to cruises or tours — were hit particularly hard. At the same time that airlines began cutting (and ultimately eliminating) commissions for selling tickets, travelers like Mr. Carey discovered they could do better without the agents anyway. Does anyone see a parable here for the music industry?