Bruhh, anyone can promote and manage. Even I can, it's not rlly a skill...
Having worked in marketing for many years, I have to disagree. Sure, it "looks" easy, enabling anyone to say they can do it, it's almost like poker in a sense... Put up an average amateur against a professional, and, while it'll be impossible to predict the outcome of any given hand, as the number of hands played goes by, you'll see the player with the most skill pull ahead.
Same for marketing. Anyone can make a crappy flyer. Anyone can select the most obvious adwords. Anyone can rent a mailing list. But not everyone will have the insight to figure out which list is most optimal, or will have the wherewithal to buy advertising on keywords that maximizes not just views, but potential actions by customers.
Case in point:
A company recently reached out to me to help with their PPC advertising. They had a relatively small budget, which was being exhausted every day, and generating no results. No sales. Not even people clicking more than one link deep into their website.
Why? Let's say they sold honda (actually a different make/brand) aftermarket parts. They were bidding on "Honda parts", "honda parts dealer", "honda replacement parts", and each click was costing a couple dollars.
I went through their site, looked up competitors, and then told him "forget advertising your brand, and forget advertising your site to the public at large, lets sell your PARTS". And that's what we did - dropped the current keyword advertising and instead started buying up keywords for as many of the manufacturers part numbers as we could get. End result - MUCH lower cost per click (as only one of his competitors was doing that, with a very small subset of their parts), more actual clicks (as his ads were typically at the top of the list), and actual product sales (as people who are searching for specific part numbers are far more motivated to make a purchase than someone searching for "honda parts" or "honda wheels").
Sure, seems obvious in hindsight. But in my experience, working with countless entrepreneurs who have launched their own websites and opted to be their own marketing teams (as, they explain, they know their products better than anyone else), I haven't had a single client say that the results they were achieving from their own efforts were at all comparable to what I was able to achieve. Not one. Because marketing is more than just putting up a link, more than renting an entire mailing list, rather than examining and evaluating each selector available.
So yeah. It's not a skill. You can do it just as well as anyone else, I'm sure.