Turn on the television, open a newspaper or surf the Internet nowadays and chances are a new financial price comparison site will pop up.

These so-called aggregator sites attract millions of consumers with the promise of searching the market to find them the cheapest deals on everything from car insurance and credit cards to gas and electricity -- all with little effort and no cost.

Adverts portray them as consumer champions bringing clarity to confusing markets and the best prices to consumers.

But just how independent and impartial are they?

Scratch beneath the surface of these sites that profess to have consumers' best interests at heart, and it is clear other forces are often at work.

The marketing conceals strong commercial motivation: these are profit-making businesses, raking in billions of pounds in commission and advertising from product providers.

Get the full story at Reuters