It's also worth noting that these services do not live in a vacuum. People seeing the story on Hacker News may well have later seen the story on Techcrunch but

It's also worth noting that these services do not live in a vacuum. People seeing the story on Hacker News may well have later seen the story on Techcrunch but skipped over it. I read all three websites daily so I would be counted where I simply saw the story first.