Twitter VS Facebook: Who's Winning the Click-Through Contest?

According to this article from Fast Company, Internet sharing trends have shifted dramatically.  While email still remains king with 55% of referrals, social networking sites saw a 10% jump.  But out of that arena, who's winning?  And how reliable is the source?

Simply put, Facebook is overwhelmingly the favorite for social network of choice with 78% of the market share.  Twitter only accounts for 5%.  Yet, the stats appear to lean towards Twitter rather than Facebook -- links shared through Facebook have a click-through rate of 287%, while Twitter boasts an astounding click-through rate of 1904%.

But what does this mean?

If the click-through rate is so high on Twitter, but it's not the social network of choice, how many clicks are really valuable?  And what about spambots or spyders checking these links -- does that have an effect on the rates?  And some savvy commenters argue that yes, the Twitter click-through rates will be inherently higher because that's all Twitter is.  Facebook has more content than just links, therefore the rates are lower.

What do you think?  Is there a simple answer for these statistics, or are the waters too muddied with other complications?

You can read the whole article and see the in-depth stats here.