Hi Evita,I'm just completing an ebook with over 90 minutes of audio and it is 30MB in size. It has a flash opening and I'm using hyprlock to allow a free preview.
I'm not too worried about download size because a 2006 study shows that highspeed usage is now at 56% http://www.consumeraffairs.com/news04/2006/09/jd_power_high_speed.html So, I am including all the audio files with the book and providing a cd option (with shipping/handling) to dialup users.
I have a steep purchase price and want to keep people from sharing the audio, so I don't allow it as a separate download.
A solution you may consider is to stream the audio from your site. I chose not to do this because our ebook will have a long shelf life and I don't want to be responsible for maintaining a site years from now if we move on to another project.
Not sure which download page you want to protect, but there are many ways to do that. I fyou are protecting the ebook download, I'm not sure what the point would be if you want it to be viral.
If you are talking about the audio, you can make it a hidden web page and put the link in the restricted area of the book. Be aware of the fact that once the audio is downloaded to a computer and not wrapped in a hyperlock envelope it will be easily shared.
Put a page in your book that allows people to "send a copy to a friend" and code an embedded email that sends the book's download link to other people who's email address has been entered - also have option of copy/paste of link so it can be easily copied into any email so they don't have to look up addresses.
If you have download restrictions from your host, check out a service like box.net to host your file. They allow password protection and unlimited downloads for about $8.00/month.
There are a lot of options to explore, and I'm only sharing my opinion as to what works best for my situation.
Hope it helps.
Mark
(Edited by Storyman at 4:22 pm on May 21, 2007)