Can Starbucks Perk Back Up?

Surrounded by rivals and new coffee trends, the Seattle chain looks to stir faster growth

Starbucks Corp. has been in a funk over the past 2½ years, posting quarterly same-store sales growth well below its historic rate of 5% or greater in the U.S., where the brand once seemed unstoppable.

The problem? The coffee culture Starbucks helped create in America spawned all kinds of competitors on both the high and low end, leaving Starbucks in the middle—and still charging premium prices.

A...