The group used mass emails and “champagne celebration nights” to encourage women to “beg, borrow or steal” £3,000 to invest in the scam.
Victims were lured by the promise they would receive a £24,000 payout when they reached the top of their pyramid chart, with organisers promising they “could not lose”.
The scheme, called Give and Take (G&T), quickly spread from Bath and Bristol to Gloucestershire, Somerset, Devon and Wales between May 2008 and April 2009.
Committee members behind the scheme pocketed up to £92,000 each, while as many as 88 per cent of their victims lost between £3,000 and £15,000.
G&T was kept under a veil of secrecy as members were forbidden from writing about it to protect the organisers.
Six women aged 34-69 have now been sentenced over the scheme receiving sentences of up to nine months.
Judge Mark Horton, who banned reporting of the case until yesterday, said: “This particular scheme caused a loss to the general public of around £19m. A number of these women suffered enormous and in some cases lifelong financial hardship due to their involvement in this scheme.
“The public need to be aware that schemes like this lead to the destruction of lifelong friendships and families and in some cases whole communities.”
Prosecutor Miles Bennett had told Bristol Crown Court: “It is clear that, blinded by the possibility of riches and quick bucks, people were quite prepared to ignore the bleeding obvious pitfalls of a pyramid scheme.”