Coinbase Earn is part of the Coinbase platform and provides you with video training called lessons on select crypto-currencies.  You receive a reward in a form of a crypto-currency straight to your Coinbase account for each quiz you successfully complete.  The videos are usually 2-3 minutes long and the quiz is usually one question in a multiple choice format, so it is worth your time considering the size of the rewards you get.  Here is a recap of the current and previously released training and their corresponding reward: 

Stellar Lumens (XLM) $10 USD in XLM (5 videos/quizzes)

ZCash (SEC) $3 USD in ZCash (3 videos/quizzes)

Basic Attention Token (BAT) $10 USD in BAT (3 videos/quizzes + installing Brave Browser)

Ox (ZRX) $3 USD in ZRX (3 videos/quizzes)

Pros and Cons of Coinbase Earn

Pros: 

• Free tokens, you got to love that!
• Lessons being offered provide some basic knowledge of the crypto currency they cover, so you earn and learn at the same time
• Advanced Lessons may be offered in the future providing additional knowledge and more earning potential

Cons:

• Although the Coinbase platform is offered in several countries, Coinbase Earn seems to be offered to US citizens first.  As a Canadian citizen, I had to join a waiting list and then was eventually offered to participate.
• As of today, you can only learn/earn on four (4) specific cryptos.  
• Your need a Coinbase account to participate.  That being said, it is free to join if you haven't, and you can qualify for $10 USD in free Bitcoins if you use my referral link: Coinbase $10 Bonus Link

Enjoy!