Loop Capital analyst Laura Champine says Wayfair reported upside to her sales and adjusted EBITDA estimates in Q1. The 80 basis points of advertising expense leverage and 805,000 net customer additions in the quarter "should poke holes in the thesis that Wayfair is overspending on customer acquisition," Champine tells investors in a post-earnings research note. The analyst expects "on-going strong growth" from Wayfair as e-commerce continues to take share from brick-and-mortar competitors. She reiterates a Buy rating on the shares with an $87 price target. The stock in morning trading is up 9% to $70.89.