Because the salesman has all the information, and you know only what he chooses to tell you. You know in advance not just the sticker price, but the dealer's invoice. You know which options are worth buying and which aren't. You know exactly what car you want and how it compares with others in reliability and safety. And if you used an Internet buying service, you may even know the best price a dealer in the area is willing to give you.
Surveys suggest that roughly half of all car buyers now consult the Web before buying.
The same is happening in airline travel. The book-buying business has been transformed as well. And other businesses are following at a breakneck pace. The Internet is still in its infancy, and as it develops, the consumer's power is bound to increase in a variety of ways. But in the high-tech market, the consumer can send far more sophisticated messages.