The BBC asked Jim Boulton why he thought Starbucks' sales have gone cold?

Jim comments:

In order for brands to truly succeed they need to have a compelling story. Starbucks had this originally, their story was that they specialised in coffee, they put the coffee first. Because coffee was at the heart of their brand, they made their customers feel like discerning connoisseurs, they were proud to be associated with Starbucks. Now, with so many coffee chains around they have no point of differentiation.

Levi's had a similar problem in the mid-90s, they lost their cult status as they moved into the mainstream and younger cleverer brands moved into their space. It was only by re-inventing themselves with twisted denim and the leftfield "flat eric" campaign that they managed to regain their foothold. Starbucks needs their twisted denim moment.

news.bbc.co.uk