For your Amusement, percentage contributions to my writing income for 2013, by payor:
Smashwords (incl Apple) 16%
(Apple is approximately 15% of this, the rest is Smashwords direct with an insignificant number of cash sales through Diesel and Sony. I sell direct through Kobo and B&N, so these are not in my Smashwords numbers.)
It should be noted that Kobo owes me money, but I have sold so few books there that I have not yet crossed the payment threshold. Likewise Createspace (the arm of Amazon that sells indiepub books in paper form.) The two combined would not be an additional 1% of revenues.
Other somewhat applicable trivia:
1) I do not use Kindle Select. (I do now, but only for a book I published in January 2014 as an experiment.)
2) I do not discuss actual dollar amounts: it's a personal quirk. However, to give you a rough idea, my average monthly income could make a reasonable car payment, but not a reasonable mortgage payment. (Reasonable, in both cases, being defined by me.)
3) I have one novel published, which has been published for more than two years. The rest are novellas, two collections of novellas, and short stories. I publish, on average, one novella or short story every six weeks or so. When I started the year I had one novel, nine novellas, two collections, and four short stories up. When I finished the year I had one novel, two collections, fourteen novellas, and nine short stories up.
4) I have another "collection," which is just two short stories in one book: I made it so I could print free books to give away at cons. (They aren't free to me: I print them for author's cost, which isn't much, and I like to think the goodwill is worth something.) As both stories are available for free, it boggles me that people actually buy a copy from time to time. Thanks!
4) I always have one short story up for free (It's the first book in a series of short stories collectively called His Lucky Break.) I usually have at least one other one up. Whenever I set a monthly volume sales record, I publish a new short story and put it up for free. When that happens the previous free one becomes a regular price story.
5) Only about 2/3 of my books are available on iTunes. Part of this is probably cover rejections and the rest is a weird technical glitch that is hard to know if you've fixed since it has to go back through Smashwords, up to Apple, be rejected, come back down, and then you get a notice many weeks or a few months later. The novel and both collections of novellas are on there.
6) Sometimes I have dreams where Oprah finds one of my books and talks about what a hideous, misogynistic piece of filth it is on television. Once in a while I wake up still making swimming motions left over from being in my dreamland Scrooge-McDuck-style money pit.