New figures that show more than one million consumers ditched the Big Six suppliers in favour of smaller companies over the past year were no surprise, according to the Energy Advice Line.
Julian Morgan, managing director of the price comparison, switching and advice service for energy users, said there had been a noticeable drift away from the major suppliers in the past year.
"Years of bad service and high prices have taken their toll on the Big Six and these figure confirm that," Mr Morgan said.
"However, there are still too many people languishing on the expensive tariffs of the major suppliers and failing to shop around for better deals.
"People are switching - just not enough of them."
Figures from energy experts Cornwall Energy show that 11% of householders - or just over 3 million customers - were buying their gas or electricity, or both, from smaller independent suppliers at the end of July. This was up from just under 2 million the year before.
Consumers now have more choice of supplier than ever before. According to the Department of Energy and Climate Change, there are now 31 energy suppliers in the UK, up from just six in 2010.
But the government and regulators have been investigating ways to encourage even more consumers to switch. Despite the prospect of saving hundreds of pounds - more for firms - by doing so, millions of families and businesses stick with the same supplier year after year.
The Competitions and Markets Authority (CMA) recently announced plans to extend its inquiry into the energy sector in order to come up with further initiatives to encourage more consumers to be proactive when it comes to choosing and energy supplier.
"It's estimated that around 40% of householders have never switched supplier and 70% are stuck on the most expensive standard variable tariff," Mr Morgan said. "So there's a long way to go.
"Even though the Big Six have failed to deliver a decent standard of service, too few customers have voted with their feet and switched. It's part of the reason suppliers have been able to get away with so much for so long.
"Customers need to engage with the market more, but we need the CMA to come up with some game-changing initiatives to open up competition and encourage consumers to do so.
"Despite some recent improvements, tariffs are still too complicated, switchting takes too long, and prices are still too high. Competition still isn't working as well as it should."
The Energy Advice Line is one of the UK's leading price comparison and switching services for business and domestic energy customers. It is also an advocate for energy market reform and has campaigned for a better deal for energy users, including calling for a ban on cold calling and changes to regulations to make it easier for all consumers to switch suppliers.
The service is completely independent and free. Consumers can quickly and simply search the market for the best available energy deals from an extensive panel of small and large energy suppliers. The service also offers a free advice line for business energy customers.
For further information visit energyadviceline.org.uk