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.
I do not think mostly are earning from signature campaign because I am seeing more volume in trading and in gambling and most of the company that we are promoting here are exchange sites and gambling sites so probably if there are losers there are also people who are making money in that business.
While there are winners too their number are a lot smaller than the number of loses, just look at gambling most people will post their stories about how they lost everything in gambling and very few will post success stories.