What this article teaches you is that if you produce something that is shareable and interesting, driving traffic to it is MUCH easier. You can use social media, you can run link building, you can share it on niche communities and nobody is going to ban it or downvote it. Actually, if your front end is great value, people will share it around without you asking. Then all you have to do is offer a free downloadable resource in this piece of content (that does not decrease its shareability as it's more free goodies) and THEN start selling via email follow up.
Since time is the most precious commodity on this earth, invest the time at the front-end so that you can reap the benefits on the back-end. This means putting in a bit of sweat equity and not getting paid today. Rather, you'll get paid somewhere down the road. And you'll continue getting paid whether you keep building that passive income stream or you stop. It's obvious that this is the preferred route, but clearly the road less traveled.
If my piece of content is so unique and valuable around hiking backpack recommendations, that other reputable outdoor websites are willing to link to it and build the page’s authority, then I’d have a very real opportunity to rank high in organic search for these search terms (meaning, my page will come up first when someone searches for hiking backpacks).