As cloud was emerging, "as a Service" offerings were primarily limited to Software as a Service (SaaS), Infrastructure as a Service (IaaS) and Platform as a Service (PaaS).

But today, service offerings have become the de facto standard for many enterprise technology offerings.

As a Service models has grown dramatically due, in part, to enterprise demand. Companies increasingly want to find third party service providers who offer software, hosting of that software in a remote data center and IT maintenance and support in a bundle, said Tom Berquist, chief financial officer of TIBCO Software Inc.

"Previously, if software was just sold to the enterprise, they would have to install it in their own data center and provide their own IT people to manage it," said Berquist. "That's an expensive investment. By purchasing these items together, as a service, and paying a monthly or annual subscription fee, they eliminate a bunch of their fixed costs."

The service model also makes budgeting easier because a company can plan on the expense and pricing is often much simpler to understand.

"As a Service is very popular today because companies can use only what they need when they need it, so this gives them the ability to ramp up or ramp down as needed," said Rob Consoli, chief revenue officer at Liaison Technologies. "It moves their capital expense to an operational expense which is also attractive from a financial perspective."

Companies that offer as a Service models also experience advantages. More companies are moving to subscription models because they can allow them to build in new efficiencies, produce steady income and allow for larger partnerships with solutions providers.

For example, Cisco CEO Chuck Robbins said last month that his company intends to create and begin testing a new network software subscription model within the "next few quarters." Under Robbins, Cisco has become more focused on subscription-based services, where it can maintain steady income as demand for its traditional hardware continues to cool.

It is likely that as a Service models in the enterprise will continue to grow in popularity and adoption. So, what can companies get as a Service? Below are seven as a Service offerings on the market today:

Security as a Service:

With cybersecurity concerns on the rise, more companies are interested in turning their defenses over to a well-qualified company that can keep an eye on their networks and allow internal IT workers to focus on other concerns.

Security as a Service can offer a number of benefits, such as constant virus definition updates that are not reliant on user compliance, greater security expertise than is typically available within an organization and faster user provisioning.

Gartner recently predicted that the cloud-based security services market will reach $4.13 billion by 2017.

Disaster recovery as a Service:

Disaster recovery as a Service involves the replication and hosting of physical or virtual services by a third-party to provide failover in the event of a catastrophe.

It is especially appealing for small to mid-size businesses that lack the expertise to develop, configure and test an effective disaster recovery plan.

Blockchain as a Service:

The complexity of blockchain—the technology that powers the infrastructure of the bitcoin cryptocurrency—makes it an ideal as a Service offering. Blockchain as a Service allows developers to provision, scale and operate blockchain environments without having to understand the underlying infrastructure. Microsoft, IBM and Deloitte are all now offering forms of blockchain as a Service.

Library as a Service:

Library as a Service was designed to provide companies on-demand knowledge and information support. The service is primarily aimed at law firms, corporations and other organizations that want to bolster their knowledge and information resources.

Surface as a Service:

Just last week, Microsoft announced that its Cloud Solution Providers and Surface Authorized Distributors can now sell Surface as a Service, allowing businesses to lease Surface devices as well as subscriptions to Office 365 and Windows 10. The concept is that companies can get the latest hardware faster without a purchasing commitment.

Containers as a Service:

Containers as a Service is a model where IT organizations and developers can work together to build, ship and run their applications anywhere, according to Docker, a Container as a Service provider.

"Containers as a Service enables an IT secured and managed application environment consisting of content and infrastructure, from which developers are able build and deploy applications in a self-service manner," Docker’s website explains.

Sorry as a Service:

Not all as a Service offerings are so cut-and-dry. There are some fun ones out there too. For example, a company called Sorry as a Service let’s people use technology to, ironically, create a more personal experience for customers.

Sorry as a Service was "born out of its founders’ mutual frustrations with crap customer support experiences," according to the company’s website.

The site allows people to order flowers, cookies and other treats for customers to apologize for a misstep, or just to say hello.