Not every article on Wikipedia is reviewed with the same scrutiny. “Black hat” editors skip the review process altogether – and their articles might not be independently patrolled for some time. Articles on different subjects also have different standards, largely because of the enthusiasm of editors. Articles about entertainers tend to be looser and sometimes much longer than articles about entrepreneurs or companies.
Promotional language is also sometimes added in to articles after the fact of an article’s initial approval, when it’s less likely to be scrutinized. That said, don’t be tempted to take advantage of this as a loophole. Volunteer editors are always scouring old articles and if they find promotional language, they might end up cutting not only that section, but also much more. Volunteer editors will also place large boxes on top of articles they consider to be promotion or reading like an advertisement – substantially devaluing the article in the minds of readers.