Do you realize that PDF documents can contain embedded Javascript code? Yes, it can. Adobe Acrobat Reader supports Javascript 1.5 extended by Adobe and it allows such sweet things as dynamic PDF content and appearance manipulation, database-driven PDF documents, multimedia, layers, 3D, Flash in PDF (!) etc.
We've seen fancy PDF documents with animations, lame PDF calculators, but where is the real beef? Where is Web2-like stuff, where are AJAXy PDF eBooks?
The platform appears to be strong enough, the Adobe Acrobat Reader market penetration must be huge, so why smart eBooks still nowhere to be seen? I can imagine lots of opportunities:
Autcomplete search field prepopulated with index words? That would improve search in huge documents, which is still a nightmare despite all Adobe efforts
Dynamic context ads in eBooks? Many would hate it, but authors and publishers would appreciate such revenue stream. Say, small text-based context ad on every 5th page wouldn't harm much. After all unlike Web pages eBooks usually have lots the real content so it must be easy to produce really well targeted context ads.
Social features in eBooks? That might be huge. eBook readers form natural social community, which is currently completely hidden. "Recent readers" sidebar, annotations, ratings, comments, chatting, "Digg this book"?
Autoupdating eBooks? "New book edition is published, get it here" or even "Book updates available, download?". Why not?
These are just few the most obvious ideas. Sure you can come up with more.
max, sure there is huge room for abuse, but that never stopped any new technology... Good enough we have FoxIt.
Stephen, I had gut feeling that must be the reason the technology still mostly unused. What about new versions? Acrobat 8 seems to be supporting Javascript 1.6.
One of the problems is Acrobat's support for javascript is completely anemic. To cite one simple example, it is not possible to even read the URL of a hyperlink.
Advertising in books is a TERRIBLE idea. I hope you understand, that when it starts, it's not going to be limited to "small text-based ad on every fifth page", it'll be more like "red-yellow-black flashing jumping screaming monkey repeated 5 times on every page"... The fairly modest banner that adobe now puts into the toolbar of the Acrobat Reader is annoying enough. Almost to the point where I am ready to switch to FoxIt Reader, or something. If they start showing advertising in books, I'll switch that same moment.