Energy Oligopoly and Profits of the Big Six

If you want the best deals in the energy market, shop around. However only 15% of customers actually actively engage with the market to switch suppliers, leaving the remaining customers vulnerable to the market power of the leading firms in the sector.

More here from the Guardian

The Guardian has greater detail here as to how the 'Big Six' energy firms have profited from privatisation to the extent that some people think that they've overcharged loyal customers, that is, those customers who've never switched supplier, by up to £2bn per year.

The companies, though, might complain that other retailers who benefit (i.e. exploit) consumer loyalty aren't monitored as closely as they are.