One thing about Microsoft these days is their relentless push to stop you using their software on-premises, or at least out of their control. "Cloud first" means local datacenter last, so I'm expecting that they're going to be slowly increasing prices to a point where the MBAs have every argument they need to move the company to Office 365. Their hosted email is admittedly very good, but it's still not "yours" and not reliable in the case of network failure, Azure hiccups, etc. I'm definitely not cloud-averse, but I do know that it really doesn't cost that much to run an Exchange server in house -- the architecture has changed enough such that it's not total black magic anymore, and the majority of the day to day admin can be done by regular help desk guys or automation tools. So, most normal-sized places with simple email requirements can get away with one guy who's good with Exchange, and it doesn't have to be their full time job until you get to a certain number of users.
Management accounting is weird -- it makes more financial sense for a company to pay and pay for years on end for a service in a subscription format, rather than buy and hold onto a software license. Same thing goes for assets -- every big company is falling all over themselves to sell real estate only to pay someone else for the privilege of occupying what was their building...all because of accounting tricks. It's so strange because it's backwards compared to personal accounting. People usually want to pay off their cars or houses and live in them without a mortgage or car loan, for example. Businesses seem to want to go to software companies and say, "Please, let me pay you forever to use your software."
Unless you need to customize your software on the database level it's going to be cheaper to host your products in a cloud environment, long term. These cloud companies can offer it cheaper based on existing infrastructure than what most small or even large companies would need to purchase in house.