How do I include a dynamic block in the product page with full page caching turned on?

Question

We would like to add a dynamic block to the product page. The problem is that the product page has full page caching (and we cannot turn that off due to speed issues). We

Answer 1

I really appreciate the answer by Vinai. In addition, I would sugggest a FPC extension by Gordon Lesti that supports holepunching. You can get it over here

For instructions on how holepunching works with this extension, I suggest you to visit this page

I hope it helps someone who is not so much familiar with the concepts.