Is content marketing becoming less effective as more people / companies do it?

The reason content marketing is effective is not because no one was doing it or it was the new thing in the marketing universe. Content marketing is effective because it gives value to the customer (when done right, not only for SEO putposes or as a tactic). In fact I would argue that content marketing when done as a marketing tactic and does not have "adding true value to the customer" at it's core, it is not content matketing, it is some form of advertising. Giving value to the customer as a way to position yourself or your business as a thought leader and the brand of choice when the time comes for them to make a purchase decision will never be less effective. With more competition, and with more and more people using marketing tactics as means to hook the customer without giving any value, the more true marketing; one that provides real value and authenticily aims to help the customer make the right choice for them, will be in high demand and more effective than ever.