https://www.binance.com/en/register?ref=INV4MNVK
Say, you have traded for a cumulative sum of $10000, then your fee would be 0.1% = $20 (fee is taken for both buy and sell trades).
By registering on the binance exchange using this link you will return 10% of the fee you pay in your trades, or $2 in this example. So, your fee would be 18$ instead of 20$.
My interest in this example is that I would earn $2 from your trades too 🙂