And as mentioned before, a much more important metric is the reach of a post. If Romney has a less influential fanbase, then he needs many more shares per post for it to reach the same number of unique users (if Obama's fan base averages 200 friends per fan and Romney's 100, then Romney could need up to twice as many shares per post).
The "talking about" metric also doesn't measure the effect of the messaging itself. The most liked post on Mitt Romney's page in the last few weeks, with over 1 million likes, is simply a graphic asking the audience to help the campaign get 5 million likes. This kind of post might be fine for rallying the base, but it has no conceivable message or talking point, nor does it target a particular constituency, other than the broad category of "Romney supporters." On the other hand, consider the data-rich infographics featured on Obama's Facebook page that are targeted toward specific issues voters. One of them spells out the number of jobs Obama would create for the wind energy industry. Another alleges regressive GOP policies aimed at women. A third outlines how Obama is making college more affordable.
Nowhere was the effectiveness of Obama's social media messaging skills more apparent than last Thursday. Shortly after Clint Eastwood made a bizarre, rambling speech to a chair, Obama's campaign tweeted out a photo of the president from behind, his head barely peeking over a chair labeled "The President." The accompanying text with the tweet? "This seat's taken," a not-so-subtle reference to Eastwood's chair. Twitter reported that it was retweeted 51,400 times. Romney's most-retweeted tweet from that week had only received 4,800 retweets. Think about that for a second. The GOP nominee, during a week devoted specifically to rallying and exciting his base, could only muster 1/10th the number of retweets as his opponent. The same image repurposed for Obama's Facebook page garnered 80,000 shares, more than any post Romney has published in the last month. More evidence that Obama's social media following is much more engaged than Romney's came Tuesday night during Michelle Obama's convention speech. Twitter reported that the first lady's "primetime speech peaked at 28,003 Tweets per minute (TPM) at its conclusion—nearly double Republican candidate Mitt Romney's (@MittRomney) 14,289 peak." Even more impressive, the president broke a new Twitter record with his speech on Thursday night, generating 52,756 tweets in the minute following its conclusion. This was highest tweets-per-minute rate for a political event ever recorded. The Republican National Convention generated only 4 million tweets over a period of three days. There were 3 million tweets about the first night of the Democratic National Convention alone, and 9.5 million over the course of the entire convention.