Last Wednesday, that consensus was blown to bits. Net-scape, a company familiar to Internet users but few others, was floated on the Nasdaq stock market in the US. The offer price had been doubled by the stockbrokers the day before, from $14 (pounds 9) to $28. It was still wildly pessimistic. The shares reached $75 on the first day before closing at $58.25.
Netscape, which is 15 months old and lost $4.3m in the first six months of this year, was suddenly worth $1.07bn - 40 times its annualised turnover. The holding of the chairman, James Clark, was worth $670m and that of the company's technical director, 24-year-old Marc Andreessen, tipped the scales at $69m.
Netscape's principal product is a World Wide Web "browser". The Web is the pretty bit of the Internet: it consists of more than 5 million pages that contain information, pictures, jokes, advertisements - anything that a user wants to put there.
Because anyone with a computer and a small amount of knowledge can set up a Web page, it is extraordinarily varied: the CIA and NASA have Web sites, but so do thousands of schoolchildren.
Originally the World Wide Web consisted only of text. But in 1993, the National Center for Supercomputing Applications at the University of Illinois produced the first graphical browser called Mosaic. It allowed users to view high-quality photographs and graphics - and in doing so it transformed the Internet from a mass of dessicated text into an entertainment medium. Users could leap around the Web by clicking on highlighted words on these pages - sending themselves off on a near-random "surf".
The NCSA offered Mosaic free to anyone on the Internet. Within the space of a year, an estimated 2 million people downloaded a copy into their computers by phone line.
It was Mosaic's striking graphics that brought the Internet to the attention of the media, and so created the fever that has surrounded it ever since. Many people decided there must be money in Mosaic - among them Mr Clark, founder of the giant computer company Silicon Graphics. He resigned from SG to get together with Mr Andreessen, the student creator of Mosaic. Last April, they founded Mosaic Communications, which in October launched the Netscape browser. At the same time, the company's name was changed to Netscape.
There are at least 20 other browsers now available, and some of their creators have made fortunes. Spyglass (the official licensee of the original Mosaic) and Quarterdeck floated and saw their share prices treble, while Spry was bought by the on-line giant CompuServe for $100m in March. But Netscape is still the big one - it has managed to grab 70 per cent of the market.
How? Well, one trick has been to give its browser away. Private users are allowed to download a copy from the Internet for free; Netscape's income comes from other companies that want to use the software to sell their own products.
This is only part of the story, though, because other browsers are available free. Netscape has also managed to establish a technical lead.
It offers a system that means it is (pretty well) safe to put a credit- card number into the notoriously insecure Internet. That has persuaded many on-line retailers to tell their customers to use a Netscape browser. Second, Netscape offers "enhanced" graphics, which mean its Web pages can be better-looking than those on other browsers.
It is quite possible that much of the puff will go out of Netscape's shares - much of the initial surge came from small investors hoping to make a killing. But the flotation has established Mr Andreessen as the new hero of the computer world. The cognoscenti already worship this tall, shorts-clad whizzkid, and the business world is now waiting to see if he will be the next Bill Gates.
Inevitably, it is Mr Gates who is also Mr Andreessen's chief threat. The Microsoft Network will be launched with the Windows 95 operating system on August 24, and this will offer its own browser as an add-on.
Netscape hopes its browser is already so well-established that it will become the de facto standard. If it does, Microsoft itself will have to switch to Netscape - and the money will really start rolling in.
All this begs the question: who else can make money out of the Internet, and will any of them be British? Firefox, based in the Midlands, sells software that restricts access to the Internet: if a company with a computer network wants its employees to have access to part of it (for example the e-mail facility) but not other parts (the World Wide Web, or games), Firefox provides the filter.
When Firefox floated on Nasdaq in May, its chairman, John Kimberley, found his stake was worth $39m, while CINVen, the venture-capital group, made a 1,000 per cent return on the money it had invested two years ago.
David Tabizel, head of multimedia at London stockbroker Durlacher, says he has a string of Internet-related companies lining up to launch on the stock market. They fall into a number of categories. Internet service providers - companies that act as "gateways" to the Net for individuals - are potential money-spinners, he says. They rely on subscriptions - but once these have covered the cost of their hardware, they are into clear profit.
Other categories include "interface" publishers, such as Netscape and "content prov- iders", who can charge for information or services on the Internet. Shops, games publishers, advertising agencies, newspapers, financial data services, bookshops . . . the possibilities are almost endless.
Mr Tabizel believes that 30 per cent of companies on the Alternative Investment Market in London will be multimedia-related - and many of these will be linked to the Internet. "A lot of deals will be based on hype," he says. "But a lot of fortunes will be made as well."
He believes UK companies are particularly well placed to ride the bandwagon. Britain's skills at software - it is the leading generator of computer games - will put it in a strong position as the competition hots up.
Despite his enthusiasm, Mr Tabizel believes things have gone too far in America. "It's all going absolutely potty," he says. "There's no question Netscape is overvalued, and my clients' expectations are going though the roof." Even if the Netscape bubble does burst, though, no one can ever again say there is no money in the Internet.