Trading is good for earning bitcoin, but you need big amount of money if you want earn big profit. In the other hand, if you have small amount of money, you can still earn money in trading, but it's not good enough and don't give big profit. For me signature campaign still the best source of bitcoin nowdays.
The way you explained is like gambling. You're investing by thinking that prices of those altcoins will boost to very high price just like gambling to win big amounts. But that is not a right way to trade. In that kind of trading, you may lose your investment than making a profit. I always go long and make some decent profit and so for never made huge profits from my trades.
Are you sure about long term?
I always though that "long term" in altcoins is a euphemism for buying them when the price is high and after it collapses sitting with losses and hoping (mostly in vain) that the price might shoot up in the future. The only thing which is worth doing "long term" in the cryprocurrency world is Bitcoin itself. All other currencies sooner or later end up at 1 satoshi