But the websites were soon overwhelmed with traffic and customers could not get the link to work.
On Wednesday afternoon, both websites displayed a message saying: “Turns out you are just as excited about this partnership as we are. We’re working fast to fill all those requests, so please come back later to link your accounts.”
Customers took to Twitter to complain.
The companies are offering 500 miles to those who link their accounts by Dec. 31 and 150 Starbucks Rewards Stars once they make a qualifying purchase.
Delta said it would be “easy for millions of Starbucks Rewards and Delta SkyMiles members to earn free coffee and miles.”
But on the first day of the partnership, many customers instead got an apology and were told to try again later.