It's the reason that you constantly see Wikipedia at the top of searches - they don't particularly care for keyword optimisation, but as arguably the internet's most trusted source of information, other websites link back to Wikipedia all the time, greatly increasing the site's legitimacy.
Yisizathu sokuthi uhlala ubona iWikipedia phezulu kusesho - abayikhathaleli kakhulu ukwenziwa kwegama elingukhiye, kodwa njengokuphikisana nomthombo wolwazi othembeke kakhulu we-inthanethi, amanye amawebhusayithi axhumeka ku-Wikipedia ngaso sonke isikhathi, ekhulisa kakhulu ukuba semthethweni kwesayithi .