Airdrops are free tokens or coins given away to those who wish to collect them. One may have to share/like on social media, or sign up via email for eligibility to claim the free tokens. If you were to collect some tokens which would then became a success, you could potentially make a lot of money.
So if you have some free time and wish to collect free cryptocurrencies, it could be a good idea to check out the sites and complete some tasks in exchange for tokens as a reward.
List of free airdrop sites
Some people think that the days have passed where one can make 200x off an investment into ICOs, such as a few cryptocurrencies this year and last.
However, some of the the next big coins may still be in development stage, being put together and about to be marketed. Keeping up to date with the new and upcoming projects, conducting your own fundamental cryptocurrency analysis before investing anything of course, has the potential to make you a lot of money off a small investment and some patience.
List of ICO sites