I've seriously considered doing websites in pdf too but still have to run into a situation dramatic enough for it to be worth it. Now that I think about it again "installing" a pdf on a pc could cover a lot of app like functionality. Most important is to make it as convenient as possible to remember your business exists and interact with it.
active (PDF) documents seem to have become a thing on eReaders, especially pen-based ones; mostly they leverage clever linking and bookmarking, and not much more, though.
