The promotion cost of selling motor insurance over the internet has fallen below that of other offline methods such as telesales, according to a survey by eBenchmarkers.

eBenchmarkers tested the performance of the online business of 16 insurers, which, according to a report, account for roughly 80% of the UK's online insurance market.

The survey found that the average advertising cost for motor insurance sold via the internet was £26, where as for telesales the cost averaged £28, a difference of seven per cent.

"This is a historic development," said Stephen Adler, eBenchmarkers co-founder. "For years people in the business have trumpeted the potential lower costs of online sales while in practice volumes were so low that other channels were able to achieve far greater economies of scale and hence lower unit costs per sale."

Adler added that in future the cost of online sales would continue to improve in comparison with other sales channels.