What motivates cost comparison sites?

[Sonyme]

I, like many others freqently get e-mails from comparison sites suggesting that by using their switch service I can save money. Is their motivation to get the best deal for me or the best commission for themselves?
I tend to ignore these as I am quite happy with current supplier and tariff.
Having erceived 3 such e-mails in a couple of days I decided to see what they could do.
I read my meters frequently and have a couple of spread sheet modules which give me a rolling 12 months usage and cost.
Using my annual usage data I submitted this to 3 different comparison sites,
and each of them informed me that I would save money by switching supplier. BUT! they all suggested a different supplier - EDF OVO and nPower.
2 of them suggested I could save money by switching to a supplier whose charges were more than I am currently paying.
I then used one of these sites but put no usage figure in just a monthly payment, and again I could save money by switching.
How can they arrive at that conclusion when they don't know my usage or whether my account is in credit or debit?
I repeat are they in it for them or us? I rather think the former.

[Zacs-Master]

They're businesses trying to make money. It's that simple.

[bednobs]

what a strange question, people don't generally set up businesses for the benefit of their customers!

[boxtops]

They're commercial business - and I'm not influenced by them. The one time I thought about changing my gas supplier, the cost went up within a few days of my deciding not to. I trust my own instincts.

What we do shop around for each year is car and house insurance, we change that almost every year because it's only an annual commitment.

[heathfield]

Banks, insurance companies, and businesses in general, are very fond of saying "Our primary aim is to provide a service for our customers". No. Their primary aim is to make money from those same customers. I get fed up with pundits on TV and in the press telling me to look up energy price comparison sites and save money by switching to the cheapest deal. Who amongst them will guarantee that if I do, the prices from a new supplier won't immediately go up, to leave me worse off than before?
That said, I find the like of 'mysupermarket.com' handy for seeking out and comparing bargain offers in those stores I might be visiting anyway. As to how the comparison websites make money, scroll down to 'Business Models'
here...

http://en.wikipedia.o...ce_comparison_service