Etsy Inc.’s quarterly loss doubled because of higher marketing expenses and the company, which runs the crafts-shopping website, said those costs would only increase in the current quarter. Etsy’s shares fell more than 15 percent to $16.27 in after-hours trading on Tuesday. The company’s revenue rose 44.4 percent to $61.4 million in the second quarter. Still, higher costs meant its net loss widened to $6.4 million from $3.2 million, or to 8 cents a share, from 7 cents.