To take market share away from its strong competitor the Douglas DC-8, Boeing custom-designed 707 variants for different customers. Boeing, for example, made special long-range models for Qantas Airways of Australia and installed larger engines for Braniff’s high-altitude South American routes. Costs of such customizing were high, so with every version of the 707, the financial risk increased. After much effort, sales of the 707 picked up. The risk taking paid off, and the 707 outpaced the DC-8 in sales.