There will probably be some different category for those that offer "information services" and don't sell products or merchandise (books excluded).Do you think he should be considered a subscriber, if he advertises his business here?
This has been suggested as an option to differentiate those members who contribute to the harm reduction objectives of the community with the information they provide (much of which is already free of charge to members). They may seek to profit with services such as books, coaching, consultations, lab testing services, etc.
They shouldn't be grouped with sources who are primarily interested in promoting product sales.