Hi Markku, I mostly mine Zcash and Ethereum, but use the gained assets to diversify the investment. Basically putting small amounts into younger less valued currencies that might have potential. Unfortunately most mineable currencies require either asics, gpus or processors. There are examples like storj and burst that can be mined by harddrives. I am a small scale miner and basically use my rigs to replace direct electric heat in my house. I will create a post about this next.