Which cities have the most Uber drivers?

San Francisco’s Uber app has become the most popular taxi service in the world and its drivers are being called upon to help the company boost its profits.

In a blog post on Wednesday, Uber chief executive Travis Kalanick called San Francisco its “most valuable city” and urged his drivers to help boost his company’s bottom line.

“San Francisco has more than 25,000 taxi-only Uber drivers, making it one of the most valuable cities for us,” Kalanicks blog post read.

“As the company grows, so too does the demand for our vehicles, and our drivers will be needed to serve this growing demand.”

San Francisco is home to many of the world’s largest tech companies, and Uber is an important part of the city’s economy, particularly in the Bay Area.

Its drivers are paid about $20 per hour, but Kalanies own company Uber Technologies has said that it’s considering a pay increase.