The women were charged up to £30,000 by the gang to repay their travel "debts".
Bordee Pitayatankul, 33, from Surrey, was jailed for 15 months. His brother Pongpoj, 31, from Paddington, was given 18 months at Southwark Crown Court.
Seven other members of the gang were also jailed.
It cannot be right in this day and age that women coming to this country should be, in effect, sold off like slaves
Gang members admitted to various offences including conspiring to launder money and plotting to control prostitution between 1 January 2005 and 21 April 2008.
Up to 70 women - some as young as 18 - worked from at least 20 brothels across London, including Bayswater, Kensington and Paddington, often going with dozens of customers a week to raise the money they were told they owed the gang.
The Oriental Gems website set up by the gang featured the women accompanied by a photo gallery showing them naked or semi-naked.
It also listed their sexual specialities with prices ranging from £150 for one hour to £1,500 for an overnight stay.
Passing sentence, Judge Christopher Hardy said: "It cannot be right in this day and age that women coming to this country should be, in effect, sold off like slaves to work in this or any other trade for free until their debt is expunged.
"Oriental Gems was exploiting on a grand scale both in the number of females on its books, or, more accurately, its website and the turnover in cash generated."
Police estimate that the business was making a "conservative" £800,000 a year at one stage, with the gang pocketing a minimum of £3.2m.
Although officers have seized £179,000 they are yet to trace huge "assets" thought to be hidden abroad.
The judge said authorities should decide whether those convicted should be deported.
Confiscation hearings will be held next year.
QUOTE FROM RELATED ARTICLE:
I have used prostitutes several times, usually from websites, as otherwise I would not have had sex for years.Men Who Sleep with Prostitutes
These girls are all far more gorgeous (and youthful) than any woman I could go out with and offer a stupendous sexual experience - with none of the payback that I have had with girlfriends in the past.
Readers, does/ did your Cyberpath see you this way? As free sex? Was he someone like Yidwithlid who saw prostitutes on his lunch hours and tried to further supplement his marriage with online sex with real (and vulnerable) women?
Or Dan Jacoby who turned his online 'support group' female friends into free porn shows and emotional toys to feed his out of control libido?
Or John Gash who used the net to find women all over the world for a free place to stay and free sex anywhere he went - while lying about love to every one of them.
Online you are NOTHING BUT AN OBJECT TO THESE MEN. And for many: a way to supplement a huge internet porn & sex habit. And you can be conveniently dumped with a click of a mouse!