It’s important to know where your traffic is coming from and the demographics of your audience. This will allow you to customize your messaging so that you can provide the best affiliate product recommendations. You shouldn’t just focus on the vertical you’re in, but on the traffic sources and audience that’s visiting your site. Traffic sources may include organic, paid, social media, referral, display, email, or direct traffic. You can view traffic source data in Google Analytics to view things such as time on page, bounce rate, geo location, age, gender, time of day, devices (mobile vs. desktop), and more so that you can focus your effort on the highest converting traffic. This analytics data is crucial to making informed decisions, increasing your conversion rates, and making more affiliate sales.
Always disclose your affiliate relationship. Most visitors will probably understand that graphic ads 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.