When we have a proper strategy and good budget to spend on you can make a decent profit out of it.But recommendation is you get onto some fresh alts and join the pump and dump game.You would surely make a profit more than expected and then you convert the alts to bitcoin while you earn profit.Just don't hold onto alts for very long,do what you have to do to make a profit and then just GTFO 
This is somewhat legit, but to make the real, big gains with the alt game you need balls to hold longer than you would expect. Like it has been said before, big gains from DRK and Blackcoin, came from guys that held the coins for 1+ month at least. I also think Monero is worth holding long term. Other than these, yes, the rest are most likely P&D shitscams.