In-store personalization is more important now than ever, especially with Millennials and Generation Z wanting to feel more like a close friend than a customer. Online start-up retailers are showing us how it’s done. Digital native brands such as Everlane, a clothing company, Casper, a mattress startup, and Eyebobs, an eyewear retailer, are making an effort to reimagine this in-store experience by putting up physical stores around the U.S.