My experiment certainly didn’t ‘fail.’ I don’t know what you meant by that, perhaps that you didn’t like the results because they were not in accord with what you stand for, but that doesn’t mean that my experiment failed.
And your claim had nothing to do with it — I always market, or promote, to put it better, all of my posts the best I can and I didn’t change any of that during my experiment, so that variable was controlled for.
Besides, I’m not doing content marketing here, I’m blogging, as in writing a blog and not content marketing for some company that would pay me for that. Apples and oranges.
As for what is content marketing — it just means companies create leads by posting helpful or interesting content (related to their business) to drive traffic to their websites. They may do that daily and use many writers for the purpose, but that doesn’t mean the content shouldn’t be great for this to work.