Bitcoin is a source of income if you holding it and never waste it on gambling, You can have a profit daily without doing anything because the price of bitcoin is daily fluctuating, My money is almost tripled since I bought some of it last january.
That's the best way to make profits but if you have some spare bitcoins then I think you should invest some of them in trading altcoins from where you can generate regular source of income by buying low and selling high and it will give you regular income and at the same time it will also help in growing your coins as most of the people are earning good amount of money from it on regular basis.