I have a side project that is getting serious traction, to the point that I am now considering how to make it a proper business.

It requires good marketing. And so I wonder : should I pay a digital marketing company, or should I try to do it myself? I lean towards the latter, but wonder if I am missing something.

To answer that question, I need to understand in depth what is digital marketing. My understanding so far is that it is:

- Website design

      I feel this is not too hard, and might not warrant paying a company for that

- Making sure my website is highly ranked via SEO methods.

      There are many guides on good SEO, so does a digital marketing agency really provide serious value there?

- Creating appealing videos

      I have some skills for that, and I feel I could hire freeelancers that could do the job more cheaply. In other words, this seems to me an easy area for me to measure the output

- Create social media communications (twitter, facebook, instagram posts).

      Is there a secret sauce here? Or is it mainly about communicating often wiht engaging visuals?

Is there any other important task that I am missing, or am I missing a critical aspect of some tasks?