Each 3rd party is the responsible its own SLA therefore any integration must rely on that particular SLA underpinning the external component.
I worked for a leading database and applications company that owns the entire stack, from hardware to applications.
The whole offer was governed by ITIL (http://www.itil-officialsite.com
). It was fairly simple to adhere to SLA since the company owned all components.
One of the main caracteristics of cloud applications is interoperability. We can call web 2.0 or any other jargon du jour.
The more components the longer the resolution chain.
Citrix publsihes its terms of service at http://www.citrixonline.com/collaboration/terms_of_service
nd posts the service status a la trust.salesforce.com at http://status.gotomeeting.com/
t also posts on Twitter.
A simple parallel highlights the impact of SLA: cellular phone operators set redundant equipment and connections, ensuring very high reliability and uptime. The benefits of investments and efforts can be wiped out in an event of a electrical blackout exceeding the Uninterruptible Power Supply autonomy or worse, a natural disaster impairing the base equipment. The very same principle applies to cloud applications.
Disclaimer: I work for Support, neither directly nor indirectly involved with vendors or SLA compliance. The views expressed are my own and do not necessarily reflect those of Marketo. I am just sharing the accumulated knowledge and concepts when I achieved ITIL certification.