Paul Good, 53, and Darryl Shellard, 45, both from Liverpool were convicted of fraud and jailed for eight and seven years each.
Lee Doran, 45, of Huyton was sentenced to 16 months for admitting fraud.
Merseyside Police said one businessman even lost his home as a result of the scam.
The fraud involved sales staff, such as Doran, posing as cold callers from the emergency services to sell advertising for non-existent publications, said police.
Shellard, and Good of Knight Street, Liverpool, targeted small firms and start-up businesses sending a sample copy to their clients who were then given 28 days to pay in full.
Det Con Clare Walsh from the force's Economic Interventions unit said some offences dated back 10 years with victims spread across the UK.
"This type of fraud is not a victimless crime - while initial amounts taken were often small, in some cases bills eventually ran to thousands of pounds, which had a devastating effect on the business and individuals involved, with one business owner even losing his own home as a result of their actions."
Shellard, of Tancred Road, also admitted perjury in a civil court.

Ross-shire Engineering has secured the potential investment across the next five years supplying equipment to Scottish Water.
The firm in Muir of Ord has already created 100 new jobs to allow it meet the needs of the utility company.
The investment has also provided additional job security to the existing 273 staff members.
First Minister Nicola Sturgeon visited the company's premises near Inverness on Monday, following a tour of Nigg Energy Park on the Cromarty Firth.
She said: "Ensuring a strong rural economy is crucial to Scotland's success.
"This funding Ross-Shire Engineering has secured provides a hugely welcome boost in providing skilled jobs and investment across the Highlands, as well as providing vital utility services to Scotland's homes and businesses.
"In particular, I am delighted they will be investing in their already strong apprenticeship job programme, providing vital training and employment to young people living in the Highlands in a competitive jobs market."
The first minister added: "Last week when I set out my Programme for Government I promised to protect Scotland's interests, particularly our economic interests, in the wake of the EU referendum.
"Driving sustainable economic growth is at the heart of that, and I am committed to ensuring this government does all it can to ensure Scotland's rural economy remains prosperous for future generations."

Madihah Taheer, Ummariyat Mirza and Zainub Mirza appeared at the Old Bailey in London on 28 April.
Mrs Taheer, 21, has been charged with assisting another to commit acts of terrorism by providing her bank details to purchase a knife.
Mr Mirza, the husband of Mrs Taheer, 21, is charged with preparing for a terrorist attack in the UK by buying a knife and other items.
Zainub Mirza from Eastfield Road, Bordesley Green, is charged with sending Islamic State propaganda videos to others.
Brother and sister Ummariyat Mirza, 21, and Zainub Mirza, 23, were remanded in custody until their next court appearance.
More stories from Birmingham and the Black Country
Mrs Taheer, of St Agathas Road, Birmingham, was granted bail with strict conditions imposed.
The trio will next appear before Woolwich Crown Court on 4 September.
West Midlands Police said the charges were not linked to March's Westminster attack.
Three conmen have been jailed for a £4.5m fraud selling bogus advertising space to small companies who were taken to court if they did not pay up.
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Funding of up to £200m has helped create new jobs at a Highlands engineering company.
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Three people have appeared in court charged with terrorism offences.