[pierrefar]

The Mashable piece alone received more than 1,400 retweets.

How many of those 1400 retweets are just bots automatically retweeting anything coming from Mashable? The dark secret of twitter marketing is that the number of tweets can be so misleading because of the bot activity. You'll also see a ton of twitter bots when you get coverage on RWW, and I'm sure others.

And yes, I've actually watched live coverage of articles I'm interested in (e.g. covering my sites) spread and checked out most tweets that came up. It's quite easy for a human to spot a bot vs real user tweeting once you look at their twitter stream. Most are bots.