In December Facebook introduced changes to the algorithm that curates which content appears in its News Feeds. The company said that the alterations would favor content it determines as "high quality," including fewer "meme photos."
Over the course of December 2013, Upworthy's traffic reduced by 25% to 67 million people and then to 48 million the following month. While a 46% drop in traffic may seem like a steep drop in two months, Upworthy cofounder Peter Koechley doesn't think so, nor does he feel that Facebook is out to get them. He likens the numbers to a "huge crazy spike" in November driven by really popular posts and that the company expected to see the decline.
Other sites, like Viralnova and Distractify, that could be categorized as posting content like Upworthy also experienced similar negative trends in traffic during December and January. However, Buzzfeed for example, a site that at least to some degree offers viral content like Upworthy, did not.
Some have suggested that this could be because Buzzfeed invests heavily in Facebook's advertising platform to drive traffic to its content. While this may be true to some extent, it's more likely because Buzzfeed, unlike the other sites mentioned, also employees respected journalists that produce engaging news content.