The ACCC believes people power has won the day in putting a lid on unfair petrol prices in Tasmania.
A "deep dive" investigation in Launceston, carried out by the competition watchdog, found retailers were raking in extra margins of between 4 and 5 cents a litre thanks to an uncompetitive market.
ACCC Chairman Rob Simms, talking on Tasmania Talks with Brian Carlton today, says RACT/United discounting prodded the market into doing the right thing.
"It has triggered a competitive response," he said.
"The combination of the RACT's leverage - the volume it can bring to United - has forced the others to respond, and so right now Launceston prices are actually pretty good compared to the mainland cities."
The report also found that the supermarket giants have been sluggish in initiating competition, preferring to let others take the lead.
The RACT's Darren Moody has told Tasmania Talks Woolies and Coles have 56 per cent of Launceston's market share, despite holding only a quarter of its outlets.
He says cunning buyups of CBD property have led to the near-domination of the market.
"They also buy very high-profile sites around the CBD, high-traffic volume sites around the CBD, so they've strategically set up their business to drive that higher volume."
A petition on our Fair Go for Fuel website garnered more than 7000 signatures before the ACCC announced Launceston as the site of its probe.
LAFM General Manager Phil McCulloch is glad retailers sat up and took notice.
"It's certainly a win for the people, both of Launceston and Tasmania," he said.
"It's something that affects the whole community, and if they're paying a whole lot more than people on mainland Australia, they've certainly got less to run their households."