Amazon is the undisputed leader of cloud computing, with 33% of the overall market according to Synergy Research Group. Its rivals include Google and Microsoft, both of which offer their own versions of cloud services. Amazon’s cloud offerings range from storage space to hosting bandwidth, processing power and a myriad of other tools used for building apps, running analytics, streaming content, data warehousing and fraud detection, among many others.

The company started putting the pieces of what would become AWS together back in 2003. The initial offering was called S3—Simple Storage Service. The idea was to let businesses avoid the expense of buying their own servers and building their own data centers by renting the hardware for a monthly fee. The customers could then access the data and software through a web-like interface that allowed them to build applications on top of them.

At the time, no one, not even Amazon itself, knew how massive a business cloud computing would be. But a few key factors set it up for success.

First, the company figured out how to make its systems secure. AWS has dozens of data centers spread out across the globe that are constantly monitored and rigorously maintained. Each region is also diversified, so a disaster that strikes one region doesn’t cause permanent data loss worldwide. This is a major selling point for the technology.

Second, the company figured out how to scale up its cloud capabilities easily and at an affordable cost. AWS customers pay for what they use, so the costs are scaled automatically and based on usage. This makes the cloud particularly attractive to start-ups and small businesses that don’t have the budget to invest in infrastructure.

Third, the company figured out how to create an ecosystem of tools for app developers, making it easy to build their own applications on top of AWS. For example, the company offers a full suite of mobile development tools that lets users test apps on real phones and run them in virtual environments. This helps companies build better-performing and more reliable applications.

Finally, the company figured out how to convince businesses that moving their infrastructure to the cloud was a smart move. By reducing the need to own and maintain their own servers and IT infrastructure, AWS allows clients to save money on hardware and staff and spend more on other initiatives.

It’s no wonder that AWS has become such a dominant force in the tech industry. But it’s also clear that the company is not resting on its laurels. Earlier this week, at its annual AWS re:Invent conference, the company introduced several new services that show just how specialized and sophisticated its offerings have become. For example, a service called Supply Chain can help customers in multiple industries get a better handle on the flow of components and goods. AWS estimates it can help save up to 30% on a typical project’s costs. That kind of efficiency is a big reason why so many companies are now choosing AWS to manage their clouds.