Allow me to proactively drain your still unattained swagger.
It's not that easy.
Think of the energy involved in posting, researching, recruiting and hiring just one marketing resource. Think of all the departments you will need approval from for each new employee - HR, Finance, Operations (new cubicle and parking spaces yes?) Generally, you will also be hiring for a primary set of skills. Your content writer will likely not have web design or SEO skills. As the digital marketing landscape becomes more complex the idea of hiring a 'generalist' becomes more far fetched.
Once you've hired that amazing talented person and exchanged all the "I'm so excited to get started/be part of your team/take us to the next level..." pleasantries that amazing talented person may turn out to be a bust. Think Johnny Football.
Hopefully that won't be the case. Remember though, that you still have the opportunity cost of training and ramping up your new employee. An new hire doesn't just magically fit into your culture.
Now, stop and think about all the things you rent. The car you are leasing, the gym you have a membership to, Netflix, Spotify, even the apartment you are living in. The company you work for is probably renting space in an office building and likely leasing office furniture and equipment in that very same building. We sometimes forget all the things we pay for on a monthly basis. And the latest employee you hired - you're essentially renting her until she (or he) leaves for a 'better offer.'
So why not rent your marketing team. Said differently, why not put a marketing agency on retainer for a month, 6 months, or even a year. Your time spent recruiting and researching a digital agency to hire will be the same time you would spend hiring one full time person for your team. More importantly, you'll hire a whole team with individuals that specialize in graphic design, SEO, website development and inbound marketing.
But what about my job Roman? I don't want want to be replaced. I hear that a lot. The last thing you will be is replaced. You will, however, have the opportunity to be more strategic, more advisory and more results oriented. You, do what you job title actually says you are supposed to do rather than worry about posting or writing a blog or building out a new e-book. Having a digital agency supporting you will elevate your marketing role.
The next time you decide whether to rent of buy something, be sure to consider what you're gaining as well as what you're giving up.