Beginning January 1, 1998, no person shall sell a device or perform a service for compensation to detect the presence of radon or radon progeny in the indoor atmosphere, perform laboratory analysis, or perform a service to reduce the presence of radon or radon progeny in the indoor atmosphere unless the person has been licensed by the Agency. The application procedures for a license shall be established by rule of the Agency. This Section does not apply to retail stores that only sell or distribute radon sampling devices but are not engaged in the manufacture of radon sampling devices or a relationship with the client for other services such as home inspection or representation as in a real estate transaction.