If you're publishing a case study as a blog or webpage then you absolutely can get some SEO juice out of it. People may be searching for 'your brand/product + review' and that can be a good keyword to potentially target. However, you'll probably only benefit from that if you have a well established brand or product and actually get branded searches. Alternatively, you can format it as a how-to article or something similar. For instance, "How to Get your First 1,000 email subscribers" and infuse a customer/client's case study as part of the article.