Even after those echoes die down, there will be an ongoing effect. Most of the readers they got through social media, as well as many from other sources, will share articles they like or wish to discuss, and each "Like" or +1 could be the one that convinces someone else to check it out. If somebody even so much as comments on one of those articles, it will be reshared to all their friends. And it just keeps on spreading, and spreading, and spreading. And if they post it to multiple networks, the effect is even larger - especially since many people tend to interact with a different group of people on each social media account. Sounds easy, right? Unfortunately, it's not quite that simple for most of us.
The original update that kicked it off was from a social media personality with thousands of followers, and even then, I only saw it because it was reshared by someone who happens to be in the top 50 in terms of Google+ followers. And I probably wouldn't have heard of that person, let alone followed him, if not for the fact that he's influential in a field I happen to have interest in. That leads to one of the most basic principles of social media marketing: target the influencers!
A comment or retweet from someone with ten followers isn't worth much, but the same thing from someone with ten thousand followers is golden, and it becomes virtually priceless if they're well-known in a field related to your product or service. If you wow them enough that they begin mentioning you regularly, that's just about the biggest success it's possible to have; you can't buy that sort of coverage! That's the whole reason that services like Klout and Crowdbooster exist - to identify influencers to be targeted, and aid advertisers in getting their attention and interacting with them regularly. They're like celebrities, and many companies treat them like celebrities, burying them in gifts and attending to their every need. Just one favorable mention is worth all that trouble and more!