It is not a correct question, airdrop is free money, so it is no such profitable, it always profit, just the matter how much is the profit.
Yes airdrop is free money, you don't have to invest to participate in airdrop just fill-up the form and join to there channel and wait till the ICO end. For me this is the good way to start. It's like planting a seed now then harvest in the future just be patience is the no.1 rule in that.