StumbleUpon, a website discovery service that at its peak had hundreds of millions of users, is closing after 16 years, one of the few remaining services from the Web 2.0 era.

Founded in 2001, StumbleUpon was a discovery engine that recommended personalized web and mobile content via its own browser, apps and plugins for leading browsers. Per its name, users of the service were able to “stumble” upon new websites and later videos based on their interests, while also including a social component that allowed them to vote on whether they liked the site they were taken to.

The company’s primary business model was to sell page views via the stumble feature. Along with recommending content based on user preferences, it would also show websites that had paid for placement as a stumble, a model that worked well for a significant number of years.

StumbleUpon changed hands a number of times during its history, first acquired by eBay Inc. for $75 million in 2007 and later spun off as a standalone company again in 2009. The company raised $17 million in a round supported by Accel Partners, August Capital, DAG Ventures, First Round Capital and Sherpalo Ventures in March 2011, funding that was used to add new features in August 2011.

Ultimately, like the social bookmark service Delicious that shut down in 2017, StumbleUpon’s appeal declined as the internet moved toward closed content silos, specifically social networking platforms such as Facebook Inc., video sites such as YouTube and services such as Twitter Inc.

In the closure announcement on Medium, StumbleUpon co-founder Garrett Camp said all accounts will be transitioned over to Mix.com, a service that “combines social and semantic personalization into one streamlined experience.” StumbleUpon users will be able to import their existing favorites, interests and tags  into Mix.com to create “Mix Collections that are easily shared with friends.”

The news comes on the same day Vevo, a nine-year-old music industry owned site powered by YouTube, also announced that it would be would be closing down its apps and standalone site to focus on distributing content on YouTube exclusively.

Something like StumbleUpon, Vevo came up against a content silo in the form of YouTube that is not only the largest video site by market share but is also an internet top 10 site within its own right. For good or bad, competing with dominant platforms like that is becoming nigh on impossible.

Image: StumbleUpon