The 'digital age' is used to describe the post-personal computer era. It first began in the 1970s with the creation of the personal computer, but has skyrocketed since 1991 and the advent of the internet. Whether we bemoan it or praise it, every part of our lives are connected. It spans from the dinner table to the corner office and everywhere in between.

We've needed to make some pretty big adjustments in our own lives because of the digital age. So, it's no surprise that how we do business has had to shift, too. Countless once-profitable business models in all industries have been forced to adapt or sink into obscurity.

Here are four ways the digital age has transformed traditional business models.

1) Engagement

Gone are the days where businesses could function solely on one-way communications. In today's connected world, it's all about engagement. This spills beyond social comments and shares, and into the very core of how humans prefer to learn and communicate.

For example, the training and development industry was completely turned on its head by the digital age. "Everything used to be instructor lead training in front of a classroom," said Curtis J. Morley, President of eLearningBrothers. "A company could only train about 30 people per instructor, per day." Today, companies create training that can be published online and reach an unlimited amount of people. Morley has seen firsthand the millions of dollars in savings this has sparked for countless companies.

Beyond the dollar savings, increased engagement results in highly-educated and trained employees across companies. Resulting in lower turnover and a more productive environment.

2) Facilitation

The digital age has taken once arduous processes and streamlined them in a way never before possible. If you've ever rented an apartment or property, you're well aware of the countless applications and paperwork necessary to complete the process. The legal nature of the process itself left landlords and tenants no other avenues to make it more palatable.

But, in the digital age, secure transferring and storing of confidential information is more accessible than ever before. Resulting in a paradigm shift within the leasing industry. Rentler is one such firm tackling this relationship facilitation head-on. The services it provides to landlords, including tenant screening and Paynless payment system, make it easier for them to find trustworthy tenants and collect payments. At the same time, Rentler's tenant-facing services turn a once time-consuming process of filling out applications to one simple, secure form submission.

When you allow technology to facilitate the processes between tenants and landlords, you make it difficult for consumers to tolerate the traditional methods in any capacity.

3) Visibility

Aiding to the element of engagement is the advent of increased visibility. Every action a consumer, or potential consumer, makes can be documented and used to serve them personalized content.

Take a look at your wrist. Most of you probably have an activity tracker of some kind strapped to it right now. And because of the company's ability to stave off competition, it's probably a Fitbit. With it, you're able to track every heartbeat and footstep you take, giving you the utmost visibility into your personal health.

Consumers have always craved this visibility into their activities, and Fitbit was able to capitalize on that desire. It combined that with advancements from the digital age, and shifted an industry once full of out-dated pedometers to one brimming with high-tech gadgets.

4) Immediacy

The undercurrent pushing these massive shifts is the element of immediacy. Human's carnal desire for instant gratification has only proved to grow with the widespread connectivity of the digital age. Millennials are conditioned to give and receive feedback immediately. That can clearly be seen by their seemingly inherent social media prowess.

Remember when gathering survey response data or consumer opinions was more akin to pulling teeth? Because of the digital age, customers give feedback at rates of frequency and immediacy that once were unimaginable. Each of their opinions has the potential to turn into a firestorm if not consistently monitored by the company.

That's where companies like Qualtrics come in, helping companies understand their digital and social vital signs. "We live in an era of immediacy, because of the digital age because people want to share their experiences," explained Mike Maughan, Brand Growth and Global Insights at Qualtrics. Maughan goes on to describe the overwhelming need for "actionable insight in the era of immediacy." Which is no easy feat. But, when feedback is effectively monitored and analyzed, companies are given the tools to address problems like never before.

Countless business models were forced to adjust at the feet of the digital age. Those that did so successfully, and catered to engagement, visibility, and immediacy, continue to reap the hefty benefits.