Differentiate tangible rewards from intangible rewards and intrinsic benefits from extrinsic benefits.

Tangible rewards are those that can be measured such as saved money, saved time or the acquisition of a desired product. Intangible rewards are those that do not have a physical presence, such as a person's desire to gain prestige, to live an easier life or gain some freedom.
Intrinsic benefits are those that readers will get automatically by complying with a request. They are tightly linked with what a writer is expecting out of the readers. Extrinsic benefits are those that a reader will indirectly get when complying with a request. They are added on to the intrinsic benefit and are relatively short-lived.