The term "first of all" is associated with the matter of content distribution in the context of content.
Term "first of all" means in different scenarios the distribution of content will be treated as first copy of the intellectual item and recipient will be counted as a first recipient.
For example: An article will be marked as "first of all" term in the case of it distributed to any of the member of subscriber list even after same article has already been given to any publisher. It happens due to the categorization of content distribution as above example shows. In above example same article is being treated as "first of all" term because publisher and member of subscriber list both belong to different category and both have distinguished characteristics.
Term "first of all" can be seen in many conditions especially during our mail magazine email list building campaign.