Coinbase has a link for consumers to share, and if you purchase over 100.00 you and the person you shared with are supposed to get 10.00 free btc. I have sent the link to four people and I have only received the free btc once. I emailed Coinbase and the reply was they don't have any control over that and they can't fix the problem. That is false advertisements. I have dealt with other companies like Stash that offer the similar incentives and they always stand behind their advertisements. You can never talk to anyone. The customer service is in dire need for an overhaul.