UK internet stocks are rather like buses. They arrive infrequently and are usually too crowded to get on board.

Despite the constant refrain that the investment bubble has to burst, each new float has punters scrambling for a share.

More than 125,000 people have registered for Interactive Investor International's (iii) flotation prospectus - with applications for shares due on Monday.

It is thought to be the highest figure for a UK online company's initial public offering (IPO).

The personal finance service plans to float later this month and is expected to be valued at between £196m and £245m - not bad for a company that was only founded five years ago.

All of these subscribers had been users of the website, the company said.

Chief executive Tomas Carruthers, who together with the group's finance director and chairman owns 29.4% of the group, said: "This is a very important moment in interactive investor's history."

The group's website allows users to compare financial products and services including Isas, pensions and insurance funds. In addition to its UK site, it has early-stage operations in South Africa and Hong Kong.

Lastminute rush

And then there is lastminute.com, one of the UK's internet darlings, which has just announced plans for a partial float in March.

It is run by one of Britain's most high profile e-commerce entrepreneurs, Martha Lane Fox.

The number of visitors to the site trebled as people tried to find out how they could be part of one of the internet's most eagerly-awaited sell-offs, causing it to crash.

The online travel and bookings agency claimed on Friday to have the second highest brand awareness among UK e-commerce companies, behind bookseller Amazon.co.uk.

It said awareness among consumers in London was 45% and 22% nationally, behind internet bookselling site Amazon.co.uk which registered 46% nationally.

The survey, carried out among 3,298 adults by telephone late last month by research company BMRB, also showed that lastminute.com was the second most visited e-commerce site in Britain, also behind Amazon.

It said almost one in 10 internet users - and more than 16% of all users in Greater London -- visited the site last month.

Analysts said Thursday's announcement by lastminute.com of a partial float in March would fuel huge demand for the shares and inflate its stock market value to £400m ($644m).

Huge demand

There has been a rush of UK stock market flotations by so-called dot-com companies since the summer, many of which have paid off handsomely for small investors.

Free access ISP Freeserve, the first UK net stock, struggled at first, falling below its 150p issue price. But in recent months it has gone from strength to strength, and on Friday was trading at 769p.

Online auction house QXL has been on of the big performers since its float late last year. Launched at 195p, it is now trading at about £15.62.

And even football site 365, a mercurial share since its flotation last November, is up 60p on its offer price at 220p.

To cater for the huge demand in such shares, internet investment funds are now springing up, such as the one run by Framlington.

Investment funds

The company's Max Kamir believes the potential of the internet means we are just seeing the tip of the iceberg at the moment.

The growth in the number of users and the services available gives companies many fresh avenues for development.

But he cautions that each float should be judged on its own merits.

"Being the first is not enough. You need to be able to build on that and provide good services, such as customer care," says Mr Kamir.

"There will definitely be some losers, but the winners will still be here in five, 10 and 20 years' time, and will be major brands."

With more and more players, the internet will eventually become like a High Street, with several companies all providing a similar service. Those which continue to grow and diversify will ultimately survive, believes Mr Kamir.

He also advises keeping on eye on companies which are not pure internet businesses, but which could benefit from it.

Risky business

It can be tempting to look on internet floats as a sure thing, but the UK is still in its infancy, with only a dozen businesses going public so far. In the US, where the market is more mature, 50% of internet shares are trading below their flotation price.

And last week, Sir John Harvey-Jones, former head of ICI, warned amateur investors not to rush headlong into internet stocks.

"You need strong guidance on how to minimise the risk and some real knowledge about the companies and their strategies," he told a conference on internet investment.

"I expect that 90% of internet start-ups will fail. While there is huge investment potential, a great many people who leap into fashionable hot stocks will get burnt."

And there will be plenty of opportunity for investors this year - it is predicted that there will be 50 UK internet flotations.

Rather than banding all e-businesses together, some institutional investors now break them down into categories to assess their prospects.

With so much choice for private investors in the coming months, it is not just about getting on the first bus that comes along, but making sure it is heading in the right direction.