One thing I've learned about making money from content-only sites is that the goal is to prove you are the expert in your niche by providing useful facts not found elsewhere and showing your personality in your writing and even videos like I do on 2create.
I can't tell you how many people have emailed me and told me they
wanted to purchase products from my affiliate link because my site helpd them and it seemed to be operated by a human and not an anonymous person looking to make a quick buck.
I don't have any real hidden or secret strategies other than just being purely honest about the information I provide. I generally only promote products I use and give specific examples of how it can help my audience and I try not to make every page a sales page.
If you are going for the content-rich site approach, remember people are going to be finding your site in the search engines so they are likely seeking information. Give them what they want (and then some) and they will be more likely to purchase products you recommend, bookmark your site, etc. etc.
The biggest mistake I see with content rich sites is that the information is either not unique enough (you can find a lot of the info anywhere) or the site lacks personality and appears to be authored by an anonymous person.
Remember, if you want people to buy products you recommend they need to trust you and you have to rely on your writing to do this.
So your goal is to choose a topic you are the expert in and come across as a genuine, helpful person that offers a lot of useful, free content.
I also try to keep my ads and affiliate links to a minimum. Some people believe that the more ads they have the better because that just increases the chances they'll make money. While that may be true in some cases, you don't want to saturate your pages with so many ads that it's obvious you just built the site to profit. You have to find a happy medium.
And all this comes from learning the ropes and getting your feet wet out here. My first site was very sales pitchy. I focused so much on promoting the latest products that I didn't give my audience useful, free info.... which is what most were looking for.
I know I've written a lot but that's what I've learned in my years of marketing content sites for profit.

And just remember, no one should give you your content. It should come from within. That's why SBI! coaches you so heavily on finding your passion.