Difference between exclusive and nonexclusive religion

Rodney Stark writes:

Exclusive [religious] firms engage in the collective production of religion... Nonexclusive firms cannot sustain collective production and therefore specialize in privately produced religious goods. As defined by Laurence Iannaccone (1995), privately produced religious commodities can be transferred from the individual producer to an individual consumer without involvement by a mediating group. New Age crystals are a current example of a privately produced commodity, as are astrological charts, or psychic healing....
Exclusive firms are far stronger organizations, far better able to mobilize extensive resources and to provide highly credible religious compensators, as well as substantial worldly benefits.
The Rise of Christianity p. 203-204