As Barack Obama and former rival Mitt Romney met in Washington on Thursday, more information emerged about how the president's victorious campaign operated—including how his digital team picked subject lines for fundraising emails.

The process was as intense as the results were surprising, according to Bloomberg's Businessweek.com.

There is no denying the Obama team's prowess when it comes to campaigning on social media and the Internet, but amazingly, even the simple choice of a email's subject line could result in hundreds of thousands of more dollars being raked in that day. And it was a skill that appeared to be lost on Obama's Republican rival.

For example, on June 26, Obama's digital team tested 12 different subject lines for a fundraising email. “I will be outspent” was the final pick and it was estimated the email blast with that subject line would bring in $2,540,866. At the bottom of that list of 12 was “The one thing the polls got right...” which was estimated to bring in just $403,603, a difference of $2,137,263. How'd they make these estimates? Well, the campaign would actually send out small batches of emails with each subject line to small groups of donors. Whichever email got the best response was then selected to be sent to everyone else.

“We did extensive A-B testing not just on the subject lines and the amount of money we would ask people for, but on the messages themselves and even the formatting,” Amelia Showalter, director of digital analytics, told Businessweek.com.

But even before Showalter released the campaign's secrets this week, some bloggers were already catching on to the Obama camp's subject line selections.

Ed Hallen studied the types of emails both Obama and Romney were sending throughout the course of the campaign and on Election Day revealed his findings at klaviyo.com. He found that one in every seven of Obama's emails had a one-word subject line. The most popular word? “Hey.”

“The one word subject line evokes a certain casualness and personal relationship and this difference seems to parallel many of the media portrayals of the candidates,” Hallen wrote.

In another post, Hallen explored what Obama's techniques told us about email marketing in general. Emails from Obama's campaign were often more engaging, Hallen wrote, with subject lines that told people to take action, such as “Things you can do now” and “Forward this.” Romney, on the other hand, had emails that were about ideas and things, America, greatness, etc.

While the 2012 election is fading into the past, political strategists looking toward campaigns in 2016 would be wise to examine this race. There is no doubt that things like the Internet and social media will play an even bigger role next time.

Photo via the White House/Flickr