I hope you did; this is a well developed promotion tool. If you've been making or selling ebooks for any length of time then you should think about how you could do something similar.
For example, if an ebook has a related titles page listing works by the author, all the names coould link to an ebookstore where the customer can buy them.
I came across this demo video yesterday on eBookNewser, and while the tricks it shows are old I thought it worth repeating. The visual aspect of the demo conveys the idea better than a mere text description.