There are a few reasons that slowly but inevitably caused the downfall of this once promising startup.

Delicious was a pretty good site before it was sold to Yahoo! in 2007. Two years later, even the founder regretted accepting the offer. Yahoo! Was already a giant back then and Delicious and its team were a very small part of it which became largely neglected. Launching the new version of the site after the acquisition was supposed to take 6 months, but, instead, it dragged on and didn’t see the light until two years later. The site was also buggy and there were frequent technical problems.

By that time other tools similar to Delicious were already dominating the sector, Pinterest, Trello, Evernote, Pinboard, Pocket, were only some of them. Besides the competitive factor, there is also to say that when Delicious was launched, it was very useful in searching for information through bookmarks a user or other registered people had already saved since Google was not as powerful as it currently is. When search engines started crawling and indexing billion of websites it became easier for people to find relevant content so the need for what Delicious offered decreased over the years.

The site went from one ownership to another until it was finally bought by its then competitor, Pinboard, for a bargain.

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Go on Reading

• Quora: Why did Delicious fail?
• Hacker News: Why did delicious.com fail?
• ZDNet: AVOS' Delicious Disaster: Lessons from a Complete Failure
• GigaOm: Oh, Delicious — where did it all go so wrong?
• Crunchbase: Delicious