Nicholas Negroponte, the American internet guru, yesterday launched an attack on the "herd mentality" of investors who have turned their backs on the consumer market on the web.

Mr Negroponte made the comments as he announced an investment in a website aimed at people wanting to swap goods. As well as injecting cash into the business, Mr Negroponte will join Webswappers.com as an adviser.

As a founder of the MIT media lab as well as the trailblazing Wired magazine, Mr Negroponte has built a reputation as one of the foremost authorities on the web.

He said: "Consumer-to-consumer websites currently carry the stigma of online retail, which completely misses the enormous opportunity of peer-to-peer commerce.

"Swapping is ideal for the net economy. It is the most extreme form of dynamic pricing, in that each party values their currency differently. Two apples you do not want can be worth one apple to you."

Webswappers, which is based in London, allows users to exhange a wide range of goods from books and CDs to cars and houses.

Swapping can have enormous tax advantages, with house swaps, for instance, incurring only £5 in stamp duty.