Sorry I'm so late posting today (long story), but I do want to pass on some info for those of you who want to self-publish but are not in love with the idea of signing on with Amazon, Apple etc. and handing over a chunk of your profits. Alternative services are coming onto the market now, like E-Junkie.com , which for a monthly flat fee will sell digital downloads of your books. You're paid directly and instantaneously for each purchase via services like Paypal, and you're not required to adhere to preset (and often obnoxious) formatting requirements. Do be sure to read carefully all the terms of service and the amount required per month to keep your title(s) in stock before you sign up.
While a direct sales service isn't for everyone (new-to-the-biz writers might want to first establish themselves via the online booksellers), if you have built a strong following and have a dedicated readership, this could be the way to sell via links from your website or blog and keep 100% of your profits. Authors who have a specialty title might profit more from selling direct as well; you won't get lost in the current deluge on the big bookseller sites.
With the direct sales approach you'd definitely have to be more aggressive with promotions and getting the word out, as you won't have the exposure you'd get on the big bookseller sites, so keep that in mind as well.