I look at my own experience. In late 1998, I helped found two organizations, Moreover Technologies, the information service, and First Tuesday, the internet networking event. The first was a passion, a business to which I was totally committed; the business is pretty robust, but my shares are only worth anything on paper. The second business was an accident, growing out of an occasional cocktail party; in mid-2000, out of greed and nervousness as much as anything else, I and the other founders sold the company, and received an unexpected windfall.

Financially, I have done better out of timing than hard work. I am not the only one. Most of the entrepreneurs who have made money out of the internet are those who, for a variety of reasons, cashed in early.

First, the born speculators, with little emotional attachment to their business, who had the detachment to recognize the top of the market. A prime UK example is Paul Sykes, an old-fashioned wheeler-dealer, backer of Planet Online, who sold the company and got out of the internet because he thought the bubble would burst. Sykes made an estimated £140m from the sale.

The gadflies: Tim Jackson, a journalist and one of the smartest UK observers of the technology industry, was early to the internet, impressed by the business model of eBay in the US, and set up an online auction service in the UK called QXL. He was the first to admit that he was a stronger generator of ideas than manager of people. Apax Partners, QXL’s venture investor, brought in a professional manager as CEO.

Bruising for Jackson’s ego, perhaps, but the switch also gave him the freedom to sell shares in the company that he would have had to keep had he remained in an executive role. Investors see share sales by founders as a worrying sign that insiders lack belief in the business; but detached or disaffected founders are given much more latitude, because their motives can be written off as personal. Jackson’s shares in QXL were worth as much as £272m at the peak. He sold enough stock to make him one of the winners of the internet years.

By contrast, Brent Hoberman of Last Minute, who worked with Tim Jackson before they fell out, has inhuman levels of commitment to the online travel business he founded with Martha Lane Fox. Admirable, to be sure, but his personal identification with the business means that he cannot cash in his holdings without raising questions about Last Minute’s viability.

The uncommitted: in which category I would have to include myself, bought out of First Tuesday while it was still valuable because I was caught up in another business. An even better example emerges from Startup.com, the hit US documentary which should reach UK screens later this year. Startup.com tells the story of govWorks, an ambitious but doomed venture designed to reinvent government services. The only people to make money out of this fiasco: the software vendors who drained govWorks dry; and the third, forgotten, founder, a rather awkward Chinese programmer who was bought out for a sum that seemed cheap at the time.

Finally, the incompetents. One of the most financially successful entrepreneurs I know is one who was never able to hold down a steady job. An intelligent but restless individual, he had bounced from career to career, which is probably why he caught the internet early in the mid-1990s. An unconvincing pitchman and obviously erratic manager, he was unable to raise venture finance for his company. When the internet giants such as AOL, Microsoft and Yahoo! came after his business, he quickly gave up and sold out. Because he had never taken funding, he still owned the overwhelming majority of the shares. There were no investors to demand their cut before he saw his gain. And he sold early enough that his lock-ins – the restrictions which stop entrepreneurs cashing in the stock of the acquiring company – expired at about the peak of the internet market.

All these stories sit uneasily beside the technology industry’s model: entrepreneur, triumphant through sheer force of will. Silicon Valley has always held that execution – precision, diligence and persistence – is the key to achievement. And, now more than ever, technology veterans claim that the rewards will accrete to those willing to stick out the current downturn.

But the record of the internet generation underlines an old and depressing truth: business success, in the internet as much as in financial speculation, is down to timing as much as any other quality. In the go-go years of the new economy, commentators talked incessantly of the first-mover advantage that accrued to the entrepreneur first into a particular market. They forgot to mention that the virtue of being, not just first in, but first out.