Here’s how it works. If you’re in the market for running sunglasses but aren’t sure where to start—or wondering if you even need a pair based on your local weather—you’re not alone.

YouTube was launched in 2005. It was founded by three PayPal employees: Chad Hurley, Steve Chen, and Jawed Karim, who ran the company from an office above a small restaurant in San Mateo. The first ...