There's a famous saying that goes 'if all you have is a hammer, then every problem seems like a nail'. This adage is known as the 'law of the instrument', and has never been more applicable to infotech than it is today.
A mere five years ago the answer to the question was: Microsoft. It frankly didn't really matter that much what the question was ... Either Microsoft had the best product (Exchange, SQL, Visual Studio), or they had a good enough product that was the standard (Office, Windows).
What a difference a few years can make. There's no such thing as a single answer to the question, and Microsoft isn't even among the answers for some of the most basic business IT questions these days (think mobile). Products from companies ranging from Google to Apple to Salesforce and dozens of others mean that businesses now have more technologies choices at a lower cost than at any time prior.
So beware ... don't fall into the trap of thinking there's only one solution for your business, and avoid service providers that only have a hammer (Microsoft) in their toolbox . The days of Microsoft only are long over, and though we think Microsoft often represents the best value for customers, there are plenty of other options that customers should carefully consider.
More choices at a lower cost than ever. Great for the customer, and great for our industry.