A few years back, a friend employed by Microsoft asked why Apple bothered to build rack servers when its money was obviously coming from MP3 players. This article suggests why Apple cares to have effective server products, and how Apple has succeeded.
Let's back up a bit: you remember that big online store that has delivered over two billion iPhone apps, over 5 billion songs (and now delivers 25% of all music sold in any format, whether digitally or on physical media, in the United States), and conducts billions of dollars in product sales annually for while serving up advertisements not only for Apple's own products but for a whole host of movies? Yeah. Imagine what the administrators of that property want in terms of hardware, remote control, and so forth. Imagine how they want to be able to recover from failure, and avoid losing transactions. Imagine how they want to save money running all that hardware and keeping it in working order.
To build outstanding hardware, Apple need only ask its own in-house administrators what is needed to make life as low-overhead and user-friendly as possible. Similar questions address quite a few of the administrative issues, as well. Apple doesn't need to speculate what big web sites need; it operates the fifth largest online store in the nation and a highly-trafficked web site subject to unexpected bursts of demand. Apple can do most of the server testing it wants in-house.
What could be easier?
Now, when someone asks why Apple would bother to build low-TCO rack-mounted servers, you know the real question: how can Apple not build them?
The next question is better: why is Apple not better at advertising the fact of its hardware to the rest of the worldwide users of server hardware? Apple's reputation isn't in servers, server customers may never have thought about Apple's Unix-powered hardware, and the products have been getting consistent accolades ("best-in-class in build quality, engineering, durability, and serviceability"; "Apple knows something its competitors don't, and after three weeks ... I know it, too"; "An objective reviewer's job is to find fault, and I've done my job. But the sum of XServe's flaws is overwhelmed by the system's unique, leading-edge, user and administrator-friendly engineering."; "Before we were running everything on a [F]edora server that had to be managed by an outside contractor who[se] availability was sketchy at best. Now I can control my whole server room from my laptop anywhere in the world. It really is fantastic. They are so powerful."). When Apple bothers to spend the kind of attention to the management tools for its server products that it spent on the last iteration of the iTunes client app, Apple will have something to write home about.