The social system for spread includes the individuals and groups in the target population (i.e., the locations where the transition from the old system to the new one takes place). Spread is successful when a new idea is adopted by the members of the social system in the target population. However, since individuals in a social system do not adopt changes at the same time, moving new ideas from the successful site to the target population is not always a simple process.

Everett Rogers places adopters into categories classified from "innovators" to "laggards" based on this temporal phenomenon and notes that the category may vary based on the change being adopted. The adoption of change in a social system, therefore, will usually start slowly, gain momentum, and then accelerate as more and more persons adopt the changes.

An individual’s willingness to adopt new ideas can also be slowed (or accelerated) by the environment in which he or she works (Brown). Spread agents should take an active role in "listening" to the target population to understand barriers to adoption and develop ways to overcome them (Dixon). This might include bringing to the attention of management the need for new equipment or arranging peer-to-peer discussions about specific issues.