NPR:

“We’ve reached the point where we’ve realized that there are other, better ways to achieve the same kind of community discussion around the issues we raise in our journalism,” he said, with money, and spending it efficiently, part of the issue. More than 5 million people each month engage with NPR on Twitter, compared to just a fraction of that number in the NPR.org comments. “In relative terms, as we set priorities, it becomes increasingly clear that the market has spoken. This is where people want to engage with us. So that’s what we’re going to emphasize,” he said.

Interesting. This is not about trolling and the high cost of moderation. Instead, it’s recognizing that engagement is moving to social media, like Twitter.