I think ICO-s are the most profitable methods of earning. BUT... depends on what ICO are we talking. IMO you have to do a full research before investing in an ICO - whitepaper, team members, do they have a product?
I'm into bitpaction.com . They have bounty and ambassador program plus multiple events and their exchange when adding new coins.
And if you hold BPS can be a good advantage in trading fees, airdrops and events.Take a look here: https://bitpaction.com/#/events/competition