To add some data around the self-publishing space overall, the best source by far is Authorearnings.com which is run by Hugh Howey (who is most famous for having become a success by giving away his book "Wool"). According to his data, the small press, indie authors and alternative press options are dominating the Amazon top 100 lists compared to prior years where traditional publishers owned 90% of the market (genre fiction doing the best overall).
On the other hand, to self-publish non-technical books, assuming you use quality service providers, you are probably looking at about $10K before factoring in marketing (according to people like Guy Kawasaki). Juxtapose that against the fact that 400k self-pubbed ISBN's were issued last year, and the true indie success story seems like the proverbial unicorn.
* Although clearly in deep technical knowledge, there will be less competition for the quality material (short supply and all that).
Of course to further muddy the issue, what market share will go to the subscription services as they become more popular? According to Authorearnings, early data shows they are grabbing a lot of eyeballs from those top-tier super-users.
On the other hand, to self-publish non-technical books, assuming you use quality service providers, you are probably looking at about $10K before factoring in marketing (according to people like Guy Kawasaki). Juxtapose that against the fact that 400k self-pubbed ISBN's were issued last year, and the true indie success story seems like the proverbial unicorn.
* Although clearly in deep technical knowledge, there will be less competition for the quality material (short supply and all that).
Of course to further muddy the issue, what market share will go to the subscription services as they become more popular? According to Authorearnings, early data shows they are grabbing a lot of eyeballs from those top-tier super-users.