Jay-Z and American Express generated some of the greatest social media activity during last week's SXSW Interactive conference. Those and other discoveries can be found in the 11-page "SXSW 2012 Social Media Buzz Report" by social media monitoring firm Radian6.

The report gives a daily snapshot of what topics, panelists and parties at SXSWi had people buzzing. The report closes with three top-level lessons learned by Radian6 staff at the conference: social media + you can drive societal and political change; the future of social media + mobile = ambient discovery; every band and brand has to focus on adding value.

Billboard.biz's 2012 SXSW Blog

While you ponder exactly what it means to add value to your social media campaigns, here are seven takeaways from the report as determined by Billboard.biz:

1. Radian6 tracked 992,423 SXSWi-related social media posts from March 9 to March 13. The sources of tweets were split 57.5% from men and 42.5% from women.

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2. Each day social activity bottomed out around 5am to 6am, peaked around noon and gently fell until the following morning.

3. Tech blog Mashable (@mashable) was the most retweeted user during SXSWi. SXSW (@sxsw) was second and American Express (@americanexpress), the sponsor of Jay-Z's performance, was third.

4. Jay-Z (@jayz) was one of the top 10 most retweeted Twitter users on each of the first four of SXSWi's five days. Jay-Z's performance at SXSWi on March 12 was sponsored by American Express and webcast live on American Express's YouTube page.

5. 30 Seconds to Mars musician and actor Jared Leto (@jaredleto) made the top 10 on each of the conference's first three days. Leto attended SXSWi for two days and seemed to have been spotted all over town - including the CNN Grill.

6. AT&T's Mobile App Hackathon and the Nokia Lab (it hosted DJ sets each evening from Saturday to Tuesday) were the #1 and #2 events, respectively, in terms of Twitter activity.

7. Panels and panelists accounted for about half of the top ten events at SXSWi ranked Twitter activity. A keynote by Baratunde Thurston (#keynotunde) and a session with New York Times executive editor Jill Abramson (#futureNYT) ranked high.