Rollercoin is having a 20% off sale right now for all miners for St. Patrick's Day. You can purchase any miner for 20% off right now. This is a great time to invest and improve your ROI. Rollercoin can be a great alternative to mining with your computer as you never have to pay for electricity or replace your hardware. You also can earn mining power just by playing games. Currently you can mine Bitcoin, Ethereum, and Dogecoin.