Pithy, but wrong.

They might not be themselves differentiators, but they are indicators of a differentiated understanding of how to design a good Q & A site that elicits high quality content from high quality contributers.

Technology is no longer the only differentiator. We've moved far enough "up the stack" that there are lots of ways to differentiate in consumer internet beyond better algorithms.

Do Craigslist, Facebook, or Twitter have anything that's, in your opinion, "differentiated"?