Short lived
ETH block time is going to get longer and run ETH unprofitable to mine by mid summer. ZEC is waiting to be dumped hardcore
Those two going down will really hurt the mining game. The BTC maximalist suggest the altcoin rise is a giant bubble
So mine altcoins right now when they are profitable and turn most of them into $$$. When they crash and hit the rock bottom turn off your miner and start buying them for $$$! Once they rebound you will be like mhhhhmmmmmmmm TASTY! Several times higher return then on BTC