“One part financial, two parts philanthropic.” That’s angel investing, in a nutshell – at least in the opinion of David Giampaolo, one of the many investors who seem happy to chip the odd spare million into ventures that range from Fitness First, the UK leisure chain, to a company that programmes impersonations of celebrity voices into satellite navigation systems.

Giampaolo, founder of investment club Pi Capital, warned anyone tempted to join a network of business angels that they should not rely on making money from their investments. He said: "The financial returns from passive angel investing are generally very poor indeed. Period."