I think the IN is perfectly reasonable and clear:
An organisation intending to offer such flights as regular business activity is not considered to meet the condition of marginal activity.
Also, flights organised with the sole intent to generate income for the organisation are not considered to be a marginal activity.’
By advertising Introductory Flights in the public domain, they fail to comply with GM2 Article 6.4a(c) of the Operations Regulation and can only be flights for the purpose of Public Transport.