Many ways to earn bitcoin, mostly people earn by signature campaign because that doesn't need any skills. But signature campaign won't give you big amount of btc.You should do trading to earn big because only trading can give you good profit in quick time.
No doubt about trading being able to fetch much more than would signature campaign, but the other side of the coin is that trading also holds more risk than does a signature campaign. At the end of the day, trading could be a case of one step forward, two steps back, but with campaigns, every step can be a landmark.