e.g. Geneseis Mining, F2 Mining etc. When you start with them you get good return for first 15-30 days, if you add more money then again they pay you good for 15-30 days. And if you don't then payouts become irregular and less. Overall you don't recover your investment even after two years. Try it.
And their support sucks
Genesis has a rating of 2.9 and Cryptonoras has a rating of 4.9.
I think that says it all.