"The milestones for that acquisition were all based around integrating that local event data into Yahoo. Yahoo didn't care about Upcoming's users—the community that created the data. Yahoo's approach turned out to be completely backwards. The value of the the company was determined by the index itself, rather than how the index was built—which is to say, by the community.
It was a stunning failure in vision, and more or less the same thing happened at Flickr. All Yahoo cared about was the database its users had built and tagged. It didn't care about the community that had created it or (more importantly) continuing to grow that community by introducing new features."