I like the free e-book format as “primers” for some topics, and I hope more are written in the future.
In my opinion, for a topic to make a good free e-book like this, you want to make sure (1) there is a high level of interest in the topic (people are looking for the information using search engines), (2) the topic is somewhat new, so people don’t yet know where to go for a definitive explanation of the topic, and (3) the topic should be something that truly rewards the reader for digging a little deeper.
I wish someone like Avinash Kaushik would write a good, free e-book primer on Google Analytics, for example. (In that case, it could basically be a re-ordering and slimming down of his selected blog posts.) Something like Google Analytics has a high level of interest; it’s a relatively young thing, and it’s practically worthless if you don’t understand some basic concepts behind it. Or, more positively, it’s something that can help you revolutionize your business if you understand it a little bit.
Here are some other topics that I think are owed free explanatory e-books:
(1) Photo editing using free and purchased software.
(3) Video production using free and purchased software
I think that as iPhones and Kindles and tablet computers keep getting more market share, more books won’t just be made available as e-books. More books will be written specifically to be e-books. They’ll incorporate graphics and videos and links, and readers will seek them out as the go-to source for more and more subjects. I think they’ll go to the e-book right after their interest is whetted by the Wikipedia article, or possibly before.