Great to see another startup using their own platform to do cool stuff! That's really the way of doin' it.
Overall, I love how Soundcloud really have focused their energy to get people use their platform in so many creative ways.
* They started Music Hack Day (http://musichackday.org/)
* They started Soundcloud Labs (http://soundcloudlabs.com/)
* They have a great App Gallery (http://soundcloud.com/apps?ref=top)
* They host hundreds of "Soundcloud meetups" (http://soundcloud.com/pages/meetups)
(Btw, here's a great talk about how they boostrapped and got people to use their platform http://vimeo.com/11420397)
