Keys was creative director of struggling smartphone maker BlackBerry for just a year. And Lady Gaga parted ways with Polaroid after a four-year stint as its creative director.

American Express has a long history of teaming up with celebrities to promote its other cards, including Martin Scorsese, Ellen DeGeneres, Sheryl Crow, Alicia Keys, Andre Agassi, Shaun White and Tina Fey.

Related: AmEx vows to cut costs

Janey Whiteside, an Amex senior vice president, said the company chose Pharrell because he's a "creative powerhouse."

"He's traveled the world, he has an amazing and curious mind," she said. "He's so much more than just a performer."

Amex would not say what it will pay Pharrell. It has vowed to cut $1 billion in costs by the end of 2017.

"We've said quite publicly that we areat the O’Connell St event. Additionally on O’Connell Street, the I BELIEVE Christmas Village from the docklands will locate a small satellite market in front of the Clerys building. It will be opening on Sunday 29th November and run through December.

Tuesday 8th December 2015 – The Live Animal Crib opens at the Mansion House. The much loved IFA Live Animal Crib, a joint initiative between Dublin City Council and the Irish Farmers’ Association will celebrate its 21st year at the front of the Mansion House from the 8th December. Entrance is free, but donations are welcome to the Mansion House Fuel Fund, one of Dublin’s oldest charities.

The Dublin at Christmas website is the one-stop-shop for all the festivities taking place in Dublin City Centre this Christmas, including shopping,