We know that four way to cryptocurrency income such as Invest ico, mining, trading and Airdrop-bounty. If you wish, you can do any of that.
If you want to mining or invest in ico and need a lot of money, it has cost-effective risks and have also profits. And if you want to do trading then you can start trading only if you have some money. Here's a little less risk and have also profit.
If you do not want to take a risk then you can start the bounty. There is no risk here only you will have to work on time and you will get your payment at the end of the job. As a payment, you can get cryptocurrency and convert them into meaning by selling them. So, I think Bounty and airdrop is very good for earning risk-free cryptocurrency profit.
Everything crypto has it's inherent risks, be it investing in ICOs, trading cryptos, participation in bounties and airdrops, etc. Saying bounties are risk-free is misleading, because it equally has its own risks. You could participate in bounties and not get paid at the end of the day and get paid with worthless coin that will never amount to anything.