The finance world is changing so fast as crypto currencies have entered in the last decades. People are using crypto currency in their lives and markets as well. In the ocean of all crypto currencies, there are many new currencies coming every day as rivers flow. So, the competition is ahead for each. With the launch of new crypto currencies, there are some challenging requirements for new crypto owners to penetrate the market, and a specific number of people use them.
So, the new crypto provides free coins to people who join them, and after the launch of these currencies on the chains, they get the value of the given coins and can trade or sell them.
This is the phenomenon behind free crypto currency mining projects. This is my view; it may be different, but I think most fall under this criteria.