Adobe made the Acrobat reader a must for viewing PDF files mainly because:
- It solved a need. Every page now printed out the same regardless of which printer or operating system was being used. It could even be made interactive for form completion.
- Adobe gave away millions of the free readers before publishers adopted the new PDF format as a standard for ebooks.
As standard as Acrobat now is, the same is not true for Flash, Shockwave, Deja Vu, and a host of other add-ons with various degrees of support.
I don't need to sit through a 2 meg Flash intro when what I want is information. Apparently, many others agree. You can add Flashblock to your FireFox browser and decide for yourself when to allow the Flash to load.