That line was famously attributed to early Facebook Inc. backer Sean Parker in "The Social Network." Nowadays, what he thinks is cool is a possible replacement for smoking: "vaping." So are U.S. tobacco giants Lorillard Inc., Altria Group Inc. and Reynolds American Inc. Expect plenty of discussion about their vapor-product strategies during earnings calls this week by investors excited about e-cigarette startup Njoy Inc.'s $1 billion valuation. Retail cigarette sales of $90 billion are about 90 times as much as the e-cig market. Lorillard, the smallest of the three in tobacco sales, is the leader with a 47% share nationally in e-cigs—slightly ahead of Njoy.