References References Costello, H. (2017, June 15). Global E-Learning Market 2017 to Boom $275.10 Billion Value by 2022 at a CAGR of 7.5% – Orbis Research. IXL Learning’s Competitors, Revenue, Number of Employees, Funding and Acquisition. Owler. New Efficacy Research Demonstrates IXL’s Proven Record of Success | Markets Insider. (2018).