PARIS — On a recent sunny morning in this city’s chic Marais district, Marion Bayod squeezed behind a tiny table at Le Cactus, a neighborhood cafe she has frequented for years. She cast a sidelong glance at a Starbucks across the street.

“I never go into Starbucks; it’s impersonal, the coffee is mediocre, and it’s expensive,” Ms. Bayod, a 35-year-old masseuse, said as a waiter greeted her by name and quickly brought her usual espresso. “For us, it’s like another planet.”

Nearly a decade after venturing into Europe, Starbucks is still laboring to lure people like her. Despite engineering a strong turnaround in the United States and growing steadily in Asia, where Starbucks is still a novelty, the company has struggled here on the Continent that gave birth to cafe and coffeehouse culture.

Now, Starbucks is embarking on a multimillion-dollar campaign to win over more of Europe’s coffee aficionados — with an upscale makeover of hundreds of stores to cater to an ingrained cafe culture, and adjusting beverages and blends to suit fickle regional palates.