This industry-leading company has been struggling in recent years.Starbucks (SBUX 1.01%) dominates the retail coffee industry, with its massive store base and global presence. Since its initial public offering in 1992, the business has usually been a wildly successful investment. But this hasn't been the case recently, with shares generating a negative 8% total return in the past three years. Adding Starbucks to your portfolio might be something you're considering. Here are three facts about this top restau ...