'The researchers found that almost 9 million articles on Wikipedia across all languages – around 15% – were orphans, effectively invisible to readers browsing within Wikipedia... In general, pageviews received by non-orphan articles are twice as many as the pageviews of orphan articles.... the researchers also established a cause-and-effect relationship between the addition of in-links to orphan articles and an increase in their pageviews.'
https://news.epfl.ch/news/orphan-articles-the-dark-matter-of-wikipedia/