It is the lone worker who makes the first advance in a subject; the details may be worked out by a team, but the prime idea is due to enterprise, thought, and perception of an individual.
We are all advertising, all of the time. If you want to sell your car, what do you do? You clean and polish it and make it the best you can. Some people bake bread when they are trying to sell their house because the smell adds a friendly feeling. Even the priest, with all his or her fervour, is advertising God. Everybody is selling.