The last step to track the impact of link building on organic search is to test and experiment with different strategies and tactics, and observe what works best for your website and niche. You can use tools like Google Optimize, Optimizely, or VWO to run A/B tests or multivariate tests on your pages and links, and measure how they affect your organic traffic, rankings, conversions, and ROI. Additionally, you can use tools like Google Tag Manager, Google Data Studio, or Google Sheets to create customized dashboards and reports that show you the impact of link building on your SEO performance. It is important to analyze the number and quality of links you build, the anchor text and context of your links, the relevance and authority of the sites you link to and from, the type and format of the content you use for link building, as well as the timing and frequency of your link building activities. After analyzing the results of your tests and experiments, you should use the insights to improve your link building strategy and tactics in order to maximize its effect on organic search.