If you are going to do content marketing you have to understand that your content has to connect with folks who are interested in what it is you are doing or selling.
And of course you want it to rank high in the search engines. So this means that we have to look at this like a chess game. Each content platform is a different piece on the chess board and can be used to accomplish different things.
A lot of companies are experts at only using one or two types of content marketing platforms. But they are incredibly effective at using those platforms. Others use all kinds of platforms but never get what they could out of them.
The platform you decide to use will of course have a lot to do with the kind of business you are running.