Purchasing agent

purchasing agent)
Decider - has the power to make the final purchase decision (e.g., CEO)
Influencer - has the ability to affect what is ordered such as setting order specifications (e.g., engineers, researchers, product managers) ...

Many people influence the decision--from the purchasing agent and company president, to technical professionals and end-users. Each of these audiences has different concerns and criteria by which they judge you.

See also: Control, Consumer, Market, Product, Wants