Starting free online earning through affiliate marketing can be a great way to generate passive income. Here's a step-by-step guide to help you get started:

1. Choose a Niche: Select a niche that you are passionate about or have knowledge in. This will make it easier for you to create content and promote relevant products. For example, if you are interested in fitness, you could focus on promoting fitness equipment or workout programs.

2. Research Affiliate Programs: Look for affiliate programs that align with your chosen niche. Many companies offer affiliate programs, such as Amazon Associates, ClickBank, CJ Affiliate, and ShareASale. Research their commission rates, product offerings, and reputation before joining.

3. Build a Website or Blog: Create a website or blog to serve as your platform for promoting affiliate products. You can use free platforms like WordPress.com, Wix, or Blogger to get started. Make sure your website has a professional design and is easy to navigate.

4. Create Valuable Content: Start creating high-quality content that provides value to your target audience. This can include product reviews, tutorials, guides, or informative articles related to your niche. Incorporate your affiliate links naturally within the content.

5. Drive Traffic to Your Website: Implement strategies to drive traffic to your website. This can be done through search engine optimization (SEO), social media marketing, guest posting, or email marketing. Utilize relevant keywords, engage with your audience on social media, and promote your content across various channels.

6. Optimize Conversion Rates: Focus on optimizing your conversion rates to increase your earnings. This can be achieved by using compelling call-to-action buttons, testing different placements for your affiliate links, and tracking your results. Tools like Google Analytics can help you analyze your website's performance.

7. Build an Email List: Encourage visitors to subscribe to your email list by offering valuable content or exclusive offers. This allows you to nurture relationships with your audience and promote affiliate products directly to their inbox.

8. Engage with Your Audience: Interact with your audience through comments, social media, or email. Build trust by providing helpful advice and answering their questions. Engaged followers are more likely to convert into customers.

9. Monitor and Adjust: Continuously monitor your website's performance, track your affiliate sales, and make adjustments as needed. Analyze which products are performing well and focus on promoting those. Experiment with different strategies to optimize your earnings.

Remember, success in affiliate marketing takes time, effort, and consistency. It's important to disclose your affiliate relationships transparently and provide genuine recommendations to build trust with your audience.