Everybody's on the Hook to succeed.
When everyone's got skin in the game, everyone works a little harder. This is true for cloud computing, too.
Since access to the cloud is a service, providers work hard to keep customers happy. Many will provide clearly documented service level agreements with penalties for under-performance.
As a customer, you're motivated to work closely with your solution provider, since they've become integral to your operations. Being accountable to one another fosters collaboration and creates an environment for trust, which ultimately benefits your business.