When I speak at social media events and conferences, my presentations are usually very well received and the audience typically finds great value in them. The main reason why (I think), is because I tell stories. My presentations always include a lot of case studies from companies that are successfully leveraging social media to grow their businesses.
But case studies alone aren't that significant, and many companies misuse them. Because too many companies want to hear successful case studies, then replicate what those companies did.
The key isn't copying another company, the key is to understand what worked, and why. Then take the lesson learned from that case study, and apply it to your own efforts.
Graco launched a blog and saw amazing results. But just because blogging has worked for Graco doesn't mean it will work for your company. The success didn't lie with the blog, it was in how Graco created and executed its blogging strategy.
Is your competitor seeing Twitter drive sales to its store? Awesome. Does that mean that you need to get on Twitter too, or that you need to understand how your competitor is leveraging social media to grow its business?
Social media case studies are incredibly valuable IF you can learn how and why social media worked in that particular instance, and apply that lesson to your own efforts. Otherwise you'll always be chasing the 'next big thing', and never quite catch it.