It was that companies talked about their products through advertisements on radio instead of buying advertising space in newspapers.

VOA: special.2011.04.14

So it's really the upfront cost to move to this, in terms of classroom space and developing pedagogy, and buying us top experiments.

因此搬到这种教室,才是最主要的花费，其中包括教室空间设置,开发教学模式，购买高级实验设备等。

麻省理工公开课 - 媒体、教育、市场课程节选