I assume that you are asking about the “market economy” approach that Finke and Stark say was used by “upstart sects” in the early United States. Those scholars argue that this method was what allowed the upstart sects to appeal to many Americans who were unchurched at the time. It also allowed them to take some members from the more established churches. The basic argument that Finke and Stark make is that the upstart sects offered more religious “red meat” and, thereby, appealed to people who had been put off by the watered down version of religion that the more established churches had offered.
The market economy approach to upstart sects argues that those sects gained adherents by giving the “consumers” what they wanted. In other words, these sects were successful because they provided a religious experience and a set of beliefs that were different from those being offered by the existing religious sects. In particular, Finke and Stark say, the upstart sects tended to offer more conservative religious teachings. The mainstream churches were much less conservative, in part because of the greater education of their clergy. They were more intellectual and less emotional. The upstart sects succeeded because they exploited that unfilled “niches” in the American religious “economy.” The mainstream sects did not change their teachings to attract the unchurched and therefore were not able to gain as many new adherents. The entrepreneurial approach of the upstart sects allowed them to increase American church membership and attendance very significantly in the early decades of the United States.
In a sense, this argument seems compelling and it seems to hold today as well. Historians tells us that the Second Great Awakening (which saw the creation of many new sects) came about in part because the older sects did not appeal as much to the people’s need for emotional religious experience. In today’s world, the Roman Catholic church is losing ground, particularly in Latin America, to evangelical churches because those churches offer a more intense religious experience. In addition, we see the LDS Church (Mormons) gaining numbers as they espouse a religion that demands much more of its adherents than mainstream religions do. It appears that, even today, people are “in the market” for a more intense religious experience and are willing to move to sects that provide that just as consumers will move to new brands of products that better suit their wants.