You aren't seeing what I'm actually talking about.
These are not applications. These are report updates. Meaning, they are posted every week to bump the thread and share links to their participation in the campaign.
This is not something done once by one person. This is done by every Facebook/Twitter campaign participant every week to keep the thread alive. If that's not incentivization to post in the thread then I don't know what is.
You are required to create new tweets (or Facebook activity or whatever) in week X to apply for week X of the bounty though. If you don't apply by posting them, in campaigns that accept submissions via posts, then you won't get anything. I take it that some users (like in the example), tend to quote their older posts for easier tracking.