The Horizen Faucet at https://getzen.cash is a fun way to learn about the Horizen eco-system.
You get small amounts of ZEN when you perform certain tasks, such as:
downloading a wallet application
make transfers with the wallet
learning how to verify an address and prove that it belongs to you
This is not an investment. This is a small incentive to users to learn more about crypto-currency in general and the Horizen eco-system in particular. We intend to continue to add features to the Faucet to further this goal.