Both of these things can be true at the same time: 1. An article is posted with informative, useful, original content. 2. An important motivation of the artic

Both of these things can be true at the same time: 1. An article is posted with informative, useful, original content. 2. An important motivation of the article author is marketing to get people to use or become aware of their product. I see no problem with this. I think it's always important to keep the motivation of the author in mind, regardless of whether it's an ad for a product or just the author themself.