This is simple addition to the Coinbase ecosystem (the Earn part was aquired and add by Coinbase from different company). It works kind of an airdrop but it is much better. For spending few seconds taking quiz (after you went through the educational videos which you can easily skipped if you want) you will get free tokens of selected crypto (for example Maker, Compound, Stellar, Graph etc.). After all quizes you can easily earn free crypto worth more than 100 USD. If you are using Coinbase I can not see any reason why you will not use the Earn part of Coinbase because free crypto is always nice and you will laso learn about selected projects. The only think you will need to keep in mind you have to be fast as there is a possibility that all free tokens were claimed already.