Why label an advertisement?

Question

Internet advertising

On some sites, the article is marked with the words:

Advertising entry

or

As an advertisement

why?

Answer 1

because hidden advertising is prohibited by the law on advertising. and marketers in social networks or on websites are trying to present advertising exactly as if it were not an advertisement, but part of a post or content. it means that in some way it is necessary to notify the user that this is an advertisement (otherwise it will be illegal). Here they are labeled with such a postscript.

Answer 2

Probably to show that there is a possibility of paid placement of articles on this site and that the content is not resource holders with articles.
Those. all ordered paid articles - so marked.
For readers, for the holder of the service and for advertisers - this is only a "plus".