I presented this at the Ignite Talks at Over-the-Air 2013: http://overtheair.org/ There is now also a video available: http://www.youtube.com/watch?v=N7zBaRiSQPY#t=37m48s Ignite Talks have a really interesting format: exactly 20 slides in exactly 5 minutes. Slides automatically advance after exactly 15 seconds; so you have to be really concise. I talked about developer evangelists best practices, which I summarise in my Onion model. My slides alone are not too useful if you did not attend my talk. That is why I paraphrase the narrative on my blog. Find it here: http://manfredbo.tumblr.com/post/62604896521/ignite-talk-at-over-the-air-bletchley-park