Cloud computing has made having the right network infrastructure in place a necessity, and Zayo Group Holdings (NYSE: ZAYO) has worked hard to build its expertise in providing the infrastructure that its customers need. Coming into Thursday’s fiscal second-quarter financial report, Zayo investors were hoping to see sizable increases in sales that could turn around a year-ago loss with a net profit. Zayo largely delivered on those hopes, but concerns about the pace of future sales growth has some investors nervous about the company’s future expansion plans.