What feature characterizes the saturation stage in spatial diffusion?

The saturation stage in spatial diffusion is characterized by the widespread adoption of an innovation, indicating that it has reached a point where additional growth or uptake is limited. This stage follows earlier phases of rapid spread and increasing popularity, at which point most potential users have adopted the innovation.

In this phase, innovations often become commonplace, and as a result, they may start to seem outdated or face challenges from newer innovations. Therefore, observing that an innovation is widely adopted is essential to understanding this stage, as it reflects the culmination of the diffusion process.

While recognizing an innovation's obsolescence can be relevant, it primarily indicates that the innovation is being phased out rather than marking the saturation phase itself. Thus, the saturation stage is more accurately defined by the extensive market penetration and adoption of the innovation.