Attention Deficit for the Internet Age

We can evaluate the persistence of the link by calculating what we’re calling the half life: the amount of time at which this link will receive half of the clicks it will ever receive after it’s reached its peak.

[...O]ne alternative theory that comes up again and again is that the dynamics of the link traffic depend on where the link is posted: do links posted on facebook last longer than they do on twitter?

So we looked at the half life of 1,000 popular bitly links and the results were surprisingly similar. The mean half life of a link on twitter is 2.8 hours, on facebook it’s 3.2 hours and via ‘direct’ sources (like email or IM clients) it’s 3.4 hours. So you can expect, on average, an extra 24 minutes of attention if you post on facebook than if you post on twitter.

~"You've Just Shared a Link. How Long Will People Pay Attention?" (bitly.com)