As an on-selling service, it provides opportunities for buyers and sellers, many of whom are scalpers, and makes its money on the mark-up, plus booking fee.
Early this month a consumer affairs magazine lodged a complaint with the Australian Competition and Consumer Commission over viagogo's tactics, especially its claim that it is an official seller and that it offers consumer protection.
Choice Magazine spokesman Tom Godfrey told the ABC that both claims were questionable at best.
"We've caught out Viagogo advertising one price and then dripping in unavoidable fees and charges at the checkout. Which means you can't redeem the advertised price," he said.
"We've also found them advertising the cheapest tickets available, when in fact they're not the cheapest tickets available.
"It's illegal and it needs to be stamped out."
New Zealand Rugby has cautioned people from purchasing tickets from unofficial sources.
"We are disappointed there are websites out there, like Viagogo, selling tickets for the Series," said Lions tour manager Nigel Cass.
"Our strong message to fans is to keep away from these secondary ticketing sites or risk missing out."
"The only official places that tickets for the series can be purchased are nzlionsseries.com, All Blacks Hospitality, All Blacks Tours and Lions Rugby Travel for UK and Irish fans."
Viagogo has been approached by the Herald for comment.