Among those sites, I still found 50em.com to be one of the most superficial ones. As some would say, working as an affiliate is similar to that of an employee, in that if the company discontinues the products, or stop the affiliate programs, the money would stop coming in as well. The hypertarget focus of 50em.com is well appreciated and a great lesson though.
You're in the right place. I strongly recommend that you go through our free training courses. While, as this lesson points out, you can market without a website, it's a lot easier to be an affiliate with a great web presence and a website at its heart. Fortunately, the costs for that are minimal. You need a domain (which you can purchase for several years at a time) and hosting (which you can pay yearly or month to month in a lot of cases).
In the first email I first send them the link to the lead magnet a second time (the excuse to email them) and ask them if they saw the offer (affiliate link). I then go on and give a bullet point list of why I think they should get it as well as maybe 1 testimonial to give it credibility and start easing into the emotional realm. I'll usually finish with a question, opening a loop making them want to open the next email.
The easiest and most common way to start building an audience for a website is via social media. Depending on your niche and industry, you can choose from Facebook, Twitter, Instagram, Pinterest and several other niche and location-specific networks. Building up an engaged and interested following on social media is a great opportunity to build relationships and once you have their trust, promote your products and services to them.
The Wirecutter is the best example of an affiliate site that I've ever seen. I wouldn't even put it in the same category as what you'd think of as an affiliate site, aside from how they make their money. Brian Lam's a great example of someone who sticks to a principle and then grinds it out to the nth degree. Can't say how many times I've used that site (and TheSweethome) for product reviews.