Qudico is a cashback site for people in the UK, located at quidco.com (I have no link with them other than as a satisfied customer).

They take a referral fee on online purchases that you make (from the supplier) and charge a £5 annual membership fee to the customer (which is only payable out of referral fees actually earned - if you don't earn that much, no one pays anything either way).

You then get the full amount of the referral that Quidco otherwise would have earned paid into your bank account. For instance, AutoEurope pays Quidco a referral fee of 8.5% which is then credited after a month or two.

My father actually got paid £20 to take out a home owners' insurance policy as the cashback exceeded the premium...