Perhaps off-topic, but does anyone know why Twitter gave up on its effort to monetize its API? There was a moment, circa 2010, when that seemed like the obvious

Perhaps off-topic, but does anyone know why Twitter gave up on its effort to monetize its API? There was a moment, circa 2010, when that seemed like the obvious move. When Twitter first began to shut down access to its full firehose, it seemed clear that there were businesses willing to pay for its information. But Twitter suddenly turned away from that idea, and focused on advertising. Considering how many sites compete for advertising dollars, it seems crazy that Twitter felt that was the right way to go. But then Facebook went down the same path, first promoting its API, then largely giving up on any attempt to monetize it. And before that, way back in 2006, I tried to build a business that would rely on Technorati's API, which they briefly promoted, then gave up on. There are a lot of companies that make money by selling information via an API. And there is tremendous competition for ad dollars. These 2 facts would lead me to expect more companies might try to make money from their APIs. But what happened in Twitter's case?