what is advertising and what is not ... ?

I saw an interesting comment of the above on a Forum Post.
Like to share it here.
   ...... posted a series of informative "articles" which seemed somewhat "self-serving" shall we say ?

So what constitutes an "advertisement" ?
... or is an advertisement to the "eye (or mind) of the beholder" only ?

It could be said that every post a person makes is a "personal advertisement" (which may have something to do with why some people post so seldom or never)

A casual mention of a favourite charity might be seen as advertising that charity (likely by someone who is at odds with the mission of that particular "charity")

So where do you draw the line on what is "advertising" ... ?

... and what is an "article" anyway ?

Is not any well composed post potentially an "article" ... ?

Food for thought.