Do not try to sell bitcoin when prices are down or lower than the price of buying time because it will hurt you.
Same, i think a lot of people will answer the same here cause this strategy is really popular everywhere, but need to understand that price is unstable and you can make a big fail someday.
Yes most of us are using this kind of method because it is very easy and you don't have to be skilled when going into trading like this.
Just follow all the instructions properly and you will become a certain professional trader once you already know the flow of bitcoins and other alt coins in terms of trading.