If all the lectures at Harvard are this good, I really wished I would have done better in high school. Listen to this just the first 15 minutes of this and there is no way a sticky presenter will not smile. This has many implications for sabha topics: karma, why do bad things happen to good people, sarva karta, prarabhda, free choice.
More importantly notice how well he is working the room with questions. This is really key. Many times in a sabha that misses the presenter resorts to questions - but he/she already has an answer, he/she does not want to explore. For example, the presenter might say "Who is the President of the United States?" That question serves no purpose other than to ensure that one person is paying attention. Another question would be "What is Karma?" Again this is not a great question since there is an answer that you are looking for and if someone strays from that answer you have to scramble to push back in the flow of your presentation. The questions being asked here are AWESOME. They are thought out. There is no one answer. He uses the questions to start with something unexpected and to get the audience to think.
He is also very encouraging to anyone who answers. He is not intimidating. He is free with praise for any answer. Depending on the audience and the speaker this is a valuable lesson.
Watch this, 15 minutes, it will make you smile. If you want more episodes, be sure to check out the site.