So, to get $10 bonus from Coinbase, you need to do the following:
1. Sign up on Coinbase through this link (important!).
2. Buy (or sell) $100 of Bitcoin. You may do this over multiple purchases.
3. Once you bought (or sold) for $100, you will get $10 in Bitcoin as a bonus.

What’s my gain in it?
When I’m inviting you (the only way to get the bonus is being invited by someone), I get a bonus too. Let’s do that beneficial for the both of us, bro!

You’ll be able to invite as well, as soon as you sign up and get your referral link.