I’m not that old — God is old — but I clearly remember the South Sea Bubble, when credulous investors pumped hundreds of pounds into shadowy companies which made extravagant promises of riches beyond the dreams of aviaries, most notoriously one which was incorporated for “carrying on an undertaking of Great Advantage, but no one to know what it is”.

The tables have turned. Today’s must-invest-in companies make no profits and no promises at all, yet they have to fight investors off with sticks.

Snapchat is in talks for funding that values it at $3.6 billion, even though it doesn’t appear to have figured out how to monetise its service yet. When we launched fotoLibra we wrote up very detailed plans on how it was going to make money, plans that we have carried out with some small degree of success, despite the appalling financial climate and the plummeting value of images. Nevertheless investors stayed away in droves.

It doesn’t seem to matter that a company has no idea how to make money. Today you make money by selling your concept to investors. Snapchat points to 9% of American youth having used its service. But 9% of American youth used to buy Eddie Fisher records. They don’t any more.

These companies are new and exciting, like hula hoops and yo-yos. I wonder how long their shelf life will be. Snapchat’s unique selling point is that it allows people to exchange photographs which then disappear. So it really is selling smoke.

When Facebook made its public offering I commented that if the Duke of Westminster decided to sell the freehold of the whole of Belgravia he’d be able to buy 18% of Facebook. I advised him not to, and I’m glad to say he appears to have heeded my advice. I believe Belgravia will be substantially more valuable in 50 years’ time than whatever the rump of Facebook will be. As for enterprises like Snapchat, Pinterest and Tumblr, I think they will be footnotes in internet bubble history.

fotoLibra, on the other hand, should be on course for world domination.