One very cool benefit of many Office365 subscription levels is the “CAL’” rights that are conferred via the O365 subscription towards on premise services. What I mean by this is that O365, for example, confers SharePoint and Exchange CAL’s that can be used for both connection to the O365 services and your own on-premise services! This is an extremely important benefit to understand if you are looking at any sort of hybrid model with services in both O365 and your own on premise servers. In fact, it is a benefit that you should consider even if you are not sure at this point that you are going to use all of the O365 services.
As Sean in our office has pointed out, it is a great way to ensure that you are licensed for both your on premise install, if that is what you insist on doing, and an O365 instance so that you can move to O365 in future without the regret of having made the investment in on premise CAL’s (which can be expensive). This does NOT imply that Exchange or SharePoint servers can be installed on premise using the CAL rights, you still have to splash out for the serve licenses as well as required internal server CAL’s for machines to talk to each other. However, you can realize substantial savings by combining the O365 CAL rights with the on premise servers. If you have ever done the math and added up all of your CAL costs involved with properly licensing something like SharePoint on your own servers, you will very quickly see the benefit of leveraging O365 subscriptions in place of on premise CAL’s. And, frankly, it is even sweeter if you just go straight to O365 and leave on premise behind; but the reality is that on premise isn’t going away any time soon for many organizations. But why not leverage at least some of O365’s benefits now?
O365 supplied Office licensing can also be used as the Office “CAL’s” on an RDS server. You have to purchase an Open License copy of Office to actually install on the RDS server as the O365 version of office will not properly install on the RDS box but, once installed, any user that has an O365 subscription that includes Office is “licensed” to use Office on the RDS server via the O365 CAL “right”. Once again, this is a pretty substantial benefit when you consider that each user subscription that includes Office confers the right to install and use Office on up to 5 devices.