When it comes to page length, I usually apply the same rules as I do to a web page, and try to keep it to two to three "screen lengths". Though I've seen ebooks with really long pages, too!
I think you have to forget the typical rules for publishing, regarding word counts per page, etc.
I'm still looking for the answer on paid/free! Here's my personal opinion - other members please feel free to contradict me! If I include ads, I wouldn't charge for it. If I want to charge, I wouldn't include ads, except perhaps for related ebooks that I'd written.
My ebook pages are generally no longer than "3 clicks" down I try to keep the pages short.
To sale or giveaway....I sell some and give away some ebooks....the ones I give away are what I like to term as "teasers." A topic that will get the attention of my target audience, give them content of interest -- and include ALOT of suggestive advertising for my "real" ebook that I want them to buy. I've had good results with freebies.
Visitors get to know the style of your work, how easy/how difficult your ebooks are to navigate, etc. Also, people new to ebooks will likely NOT buy from you until they're sure exactly WHAT an ebook is.
Some of my customers have mentioned how much they enjoyed this freebie or that one -- so I know freebies work! I've also made a good deal of commission with CB links included in freebies.
With any business, it is up to the individual owner of said business to ensure the success of the business. You may make more or less than any sample figures or results that might be quoted on our web sites or other publications. All business involves risk, and many businesses do not succeed. Further, Answers 2000 Limited does NOT represent that any particular individual or business is typical, or that any results or experiences achieved by any particular individual/business is necessarily typical.
I try to keep the pages short.