Dave McClure (advisor for slideshare) lead an amazing panel on “startup metrics for pirates”. I love his AARRR framework: it really helps you understand what the “next thing” is that you have to work on as a web startup.
Many other SXSW presentations are available here.
jonathanboutelle.com 
thanks jonathan!
btw, the updated presentation we used for the panel (with case studies) is now posted here:
– dmc