Another strength of Canvas for creatives is the way that it reflects the ideas process within agencies. Ideas are usually thrown around at agencies and are built on and changed a number of times. The backbone for Canvas is that you can consistently remix ideas.
The system of contributing is very easy too, working on a very similar system to MS Paint which means that most people can get involved with the system. Here is a great speech from Moot explaining Canvas at SXSWi.
TCO's Rhys Edwards has already had success with one of his images Hipster Libyan trending on canv.as and getting over 110,000 views on Reddit in 24 hours. I have two invites for Canv.as so let me know if you are looking for one