Content marketing is a great SERP booster if done right
Everyone is trying to rank higher in the search engines, if you're not, you're already falling behind your competition.
I've been doing tests with content marketing and some things work well while others are complete garbage and should be avoided. Don't worry, I'll talk about both
Content marketing can help you build your brand fairly well if you do it right. Targeting high authority websites can obviously help boost your rankings, but if you don't have the writing skills to convert your readers into sales, you'll be pretty upset in a quick amount of time. Write it once, and write it well
Doing guest posts on popular blogs isn't as easy as it sounds because you're at the mercy of the blog owner. If they think you're worthy they will let you post on their website, but it can't be a promotion post. you will have to add quality content that the blogs readers will like and then you can add a link in your signature and possibly the content of you post.
Doing this manually will help you get high quality content on various websites and blogs in order to boost your rankings, sales, and traffic. You can use software to push out your articles, but don't spin them. Also, you might get your articles removed pretty quick due to them not passing copyscape. Even if you write it up yourself, it could go live on a different website and indexed before a different blog or website owner goes to approve it.
If you do this wrong you could actually be hurting your own rankings. This is because you pay someone to blast out thousands of posts including the same content in each article and if they do get accepted, it's usually not on the best of the best websites and blogs.
Low quality content will not get accepted on high authority websites and blogs. You need to know how to write, or hire a writer, before you contact a website or blog for a guest post.
Posting on random websites can hurt you if they are not in the same niche. This is one of the same reasons I won't use software to push a unique article. They are never 100% guaranteed to get your article on niche related websites.