What type of innovation is ride sharing?

http://toddwschneider.com/posts/taxi-uber-lyft-usage-new-york-city/ http://toddwschneider.com/posts/analyzing-1-1-billion-nyc-taxi-and-uber-trips-with-a-vengeance/ Based on Todd's in-depth work, we clearly see 'disruption' of 'taxi travel' in some form but what kind? Clayton Christensen speaks about 3 forms of innovation; disruptive, sustaining...