More and more, businesses are becoming open to externalizing anything not a core part of their business.* Let's say a company sells cooking grills. It no longer has employees, or department, handling email.

They contact 'Turnkey Enterprise iSolutions Ltd.' which handles everything email for $5 per address**, per month. After all, this company sells grill (their core business) not manage emails. Why worry about server mainteinance, create user accounts, schedule backups, or handle spam? The executive simply wants to make better grills and sell them to more people.

So, let's say email-as-a-service is proposed. Let's say the grill company (GrillCo) needs 400 email accounts. Since they do not buy email servers, or hire spam gurus, there's no large, initial investment. They test it with one department (accounting). If the ten people in accounting like it, they expand it to everyone's email. This eliminates risk for the buyer.

Now, is this a better way? Truthfully, anyone willing to provide a definitive answer, either way, is crazy. It may work for some situations, it may not work for others. There is a reason these are discussed, and may become more and more popular. Simply, for better or worse, cost-cutting is highly rewarded at the executive level. If you run a publicly-listed company, and do not appear to be "cost-oriented", you raise suspicions among the board of directors, shareholders, and Wall Street.^

* Whether or not this is true I don't know, but that's what they are proposing.

** I'm picking a number out of thin air.

 ^ I'm not saying it's good, simply largely how it is.