Yes holding bitcoin for long is a good way to make money cause it just went up from 550 to 600 for example, so if you had 10 you would've made 500 profit. Anyways they will rise higher and higher resulting into a higher percentage profit. If they drop be sure to buy even more because after a drop they will get up above the previous price before the drop.
In order to make profit, you have to start selling some coins. If you keep holding and you see your coins have gone up in value, then it's basically only a statistic showing the higher value, and that's it. That's also the same for coins going down in value. You only lose when you are selling your coins. Basic things that a lot people don't seem to know, or care about.
. Just kidding, anyway you can earn a profit from this kind of method but it will never come close to the profit of those that are actively used to earn more profit. So those with the capability to put up a business and make it succesful willl reap the profit 100x or more than those who just hold it. 
