The U.S. Postal Service Just Got a Side Hustle Delivering Groceries. Do You Have Another Gig? Leverage the skills you have into some side income. Teach a course. Do something you know.

Just the other day the United States Postal Service made headlines by getting into the grocery delivery business. Yes, at a time when most people are writing off the organization as old and obsolete, it's not only saying no to that notion but continuing to reinvent itself.

The side gig consists of delivering groceries from 3 a.m. to 7 a.m. for Amazon. The two-year market test, called Customized Delivery, is restricted to San Francisco but could expand nationwide.

What many people may not know is that the postal service also serves as a subcontractor for Federal Express and the United Parcel Service, delivering 2 million packages a day on average for the two other shipping giants.

So don't count the postal service as out just yet because it's doing whatever it takes to stay innovative and relevant in an age when online messaging has overtaken the way Americans choose to communicate. The organization is embracing change. It's pivoting to stay top of mind and focusing on what it can do. Other companies as well as entrepreneurs should take note. (Disclosure: My job as a federal employee is to write articles for government workers, including postal workers.)

So if the federal government sees the need to start a side hustle, what does that tell you?

Ding!

You guessed it. You need to start one, too, preferably, as soon as you finish reading this article.

Related: How to Brand Your Side Gig While Working a Full-Time Job

There are tons of ways you can start a side business and I could list the ways, but you've probably seen that same old list before. It looks a little like the one below and you could start now and become one of the following:

1. A graphic designer

2. A photographer

3. A dog walker

4. A computer programmer

5. A singer

But is that really the best way to leverage the skills you already have?

Take the example of the U.S. Postal Service. It's not starting a completely different side hustle. The organization is already in the delivery business, so it's chosen to align itself with what's already in its wheelhouse. It's leveraging its existing expertise to access a new revenue stream.

How does this apply to you? Well, consider what you currently do for work and ask, How can I leverage what I already know? One of the best ways to do this is to teach others what comes easily to you. If you think you don't have anything to teach, answer this question posed by blogger and podcaster Sean McCabe: "Is what I know more than what I knew when I first came into this field?

He continued, "If the answer is yes, and it usually is, then you've got something to teach." Every aspect of what you do and have done can be taught, according to McCabe.

The great thing about this is that you don't have to do any extra work to learn something first because you already know it. In my opinion, the fastest way to earn a side income is to start by teaching what you already know.

I recently polled my email list about areas they'd like to start a side business in. I got a response from Brian saying he does a lot of training at work. He wanted to know how he could develop this into a side business. He's asking the right question. He already knows a ton about training, so he should develop a course around this skill and not take the time to learn about photography, say, in order to earn side income unless he knows about it or is passionate about it.

If you work as a photographer, teach a course on photography.

If you work as a fitness instructor, teach a course about how to become a fitness instructor or a related topic.

The best part about this is that you can do this all online. You can start your own YouTube channel, teach directly from your blog or via a podcast.

Related: YouTube Really Is the New Silver Screen

Blogger Nathan Barry regularly writes about design and marketing. For years, he had the dilemma that many entrepreneurs have. He couldn't figure out how to get attention for his business products because no one knew they existed. He overcame this problem when he started to teach. When he taught about design by putting tutorials on his blog, he gained more email subscribers. He was able to leverage his teaching into an ebook, pulling in more than $12,000 in the day after launch.

Still not convinced? Check out Pat Flynn's Smart Passive Income blog. What I admire about Flynn is his generosity. Everything he learns he teaches to his audience. He has offered tutorials about how to start a podcast, build an email list among other thing. At the top of his site, he lists exactly how much money he made that month. He's honest and transparent about things. Because he gives so much to his community by teaching what he knows, people always thank him by supporting his projects.

Now it's your turn: What expertise do you have that you can leverage into side hustle income? Heck, I'm even getting into the act. I'm sharing my insights about this very topic in an upcoming course I've titled "Teach Online: How to Create Side Hustle Income Leveraging Your Existing Skills."

I became inspired to offer this course (my first!) after last year's government shutdown affected many federal employees. I wanted to create a course that could help them in the event this happens again.

So take a page from the postal service and consider leveraging what you already know and teaching it. The postal service's slogan is "We Deliver for You" and from the looks of things, it will be doing that for a very long time. So what about you?

Related: 7 Steps to Launch Your Freelancing Career Full-Time