I will choose campaign. No money will be required to campaign and there is no risk. I earn good money by bounty. On the other hand, trading and gambling both are risky and capital required.
That's a good choice. I mean, when you don't have money or don't want to spend your own money, campaign is a good way to do. Once you earn some money, you can use it to trading, gambling and mining. If you want to spend your own money, then do trading, it's good imo.
This strategy I have been used now, I join the signature campaign(paying btc weekly) to have a capital in trading and sometimes gambling as well. But only signature campaign paying btc is felt safe to join. I had join bounty several times but until now there token still did not profitable, did not have a value yet on the market for more than a year. So, joining a signature campaign on bounty still, have the risk.