Marketplace ministry typically refers to evangelism or other Christian activities that are targeted towards the secular workplace, as opposed to homes, churches, or specialized venues (e.g., crusades). It can also refer to particular parachurch organizations that focus on such ministry. The term probably entered circulation in the 1980s, though groups with similar emphases (e.g., the Christian Business Men’s Fellowship) have been around much longer.
While the original use of the term is primarily evangelical in nature, transformationalism has appropriated many of the same structures, often under the term marketplace redemption.
The term “Marketplace Ministry” does include ‘evangelism’ however it is much broader than that. It speaks to the fact that any Christian can fulfill their desire to serve God in the workplace. This can assuage a lot of guilt in those that want to “go into full-time ministry” as they realize they are already in “full-time” ministry.