A few weeks ago I sold a digital game code (Watchdogs 2) through ebay for the first time ever, and sent it via the ebay message system. Today, the buyer did a chargeback. They have 100% positive feedback because they wait until the feedback can't be modified anymore (30 days) before doing a chargeback. And apparently both ebay and paypal have no protections at all for sellers of digital goods. The only way to sell digital goods and have some sort of seller protection is to ship them physically (envelope with the code written on paper inside) with tracking information.
I made this thread just to warn anyone who may consider selling digital goods on ebay / using paypal in the future.