I must admit there are loads of sites that offer you free service, free mining but then again it isn't free at all, commission is high and before you withdraw your earnings they shut the site down and run with your money.
I join the site https://freebitco.in/?r=1957046 a while back, and so far did not invest a single penny and mined £47.00 at the current rate for bitcoin. So far so good, but it is very slow process. And when people do join under the referral program they don't mine every day. That site paid me every time without a fail when I accumulate for payout. This is the only site I can't fault for non payment.
Do you use this site? What are your experiences with them?
If you want to join them, here is the link: https://freebitco.in/?r=1957046