Yes because the price sky rockets from time to time.
I`m holding my bitcoins for 6 months and the price increased from 600$ to 730$.
I can`t say it sky rockets,but it`s a good increase.
Yes,it`s a good way,but you have to buy and sell at the right time.
Profit is profit. May I ask why you didn't buy before the price reached the $600 levels? You had enough time to buy your coins ar much lower price levels than where you bought your coins at this time. Common mistakes are that people wait too long with buying as they hope the price is going down even more. And when the price isn't going down people mostly buy in panic to not fall behind and miss out.