gambling is not a way to earn bitcoin online and even if you can earn something out of pure luck it is definitely not an stable way to earn bitcoin.
for more reliable way you have to do some jobs based on your skills. trading is one of these ways which requires some skills which everybody can learn.
Gambling will always be a good method it you have too many coins and you want to get rid of some of them.
The house always wins.
Skills are really better. But where can I learn those skills?
I disagree on this,unless you invest in casino houses, you cannot have a steady income in gambling. It isproven many times that when you are gambling there is aa greater possibility that you will lose agains the house. It would be a steady income with signature campaign.