I've been doing affiliate marketing – successfully – for well over a decade. While I earn affiliate income from this website, I've made the bulk of my affiliate revenue from selling real users products and services – in multiple niches - that have nothing to do with the making money online niche. I've been nominated as Affiliate of the Year three times in the Affiliate Summit Pinnacle Awards – taking home the award in 2016. I've spent the last decade+ teaching people how to find success with affiliate marketing - based on my own experiences - as well as advocating for the industry as a whole. I'm often blunt and can sometimes be controversial, but I'm also 100% bullshit free.
Always disclose your affiliate relationship. Most visitors will probably understand that graphic ad will lead to your getting paid, but if you write a review or use an in-text link as a recommendation, you want your readers to know that may lead to compensation as well. This ensures you retain transparency and trust with your readers, but also, it's required by the FTC's endorsement rules.