Affiliate Book Sales can earn you even higher book royalties. Some tricks, though.
The simple approach is to get your distributors to pay you affiliate sales fees on top of your royalties. None of them do it the same way, some don't at all.
What this will give you is sometimes another 6-8% on top of whatever you are already getting - nice work when you just send readers from your web page...
Here's the breakdown:Kobo - yes, via Rakuten - http://cli.linksynergy.com/cli/publisher/links/deeplinks.php
B&N - yes, "private" (Rakuten) - http://affiliates.barnesandnoble.com/join-now/
iTunes - yes - https://signup.performancehorizon.com/signup/en/itunes - http://www.apple.com/itunes/affiliates/resources/documentation/itunes_app_store_affiliate_program.html
Amazon - if you live in the right states
GooglePlay - no (but they say you can run Adsense on your site - FWIW)
LeanPub - yes, 50%, but it's a net wash - https://leanpub.com/affiliates - https://leanpub.com/affiliateterms - (for self-publishing authors:) http://blog.leanpub.com/2014/03/introducing-the-leanpub-affiliate-program.html
Lulu - not at this time.
Smashwords - yes, 11% - https://www.smashwords.com/about/affiliate - https://www.smashwords.com/about/smashwords_affiliate_documentation
The point of giving out affiliate links is to increase your royalties. True, when you are getting 70% or so for every sale, that's not bad and it may not be worth the extra effort. However, when you are having to take a lower royalty for any reason (such as selling 99-cent "loss leaders" or re-publishing "public domain" books under their original title and author) then every cent counts.
(One wild example: on Kobo, you are required to declare any derivative public domain work which contains the entire book as public domain and get only a 20% royalty. If you then publish that book for $3.99, you get a whopping 79-cent pay-out. However, if you send buyers to Kobo via an affiliate link, you can get an additional 6% - which at least brings you up to 26% for your work. That's only when people use your affiliate link, but it's better than nothing.) But see this blog post about Kobo as well - it's not all my public domain sour grapes: http://eboundcanada.org/index.php/resources/tutorials/171-a-publisher-s-guide-to-becoming-a-kobo-affiliate
If you only have a few works, and get most of your traffic from personal referrals, this would be worth a little bit for you. (For those of us with deeper backbench - lists of multiple books - this might be more trouble than it's worth. Finding more books to publish would probably be more profitable.)
The real use is in getting other people to use affiliate links when they send traffic to your book. You can get them to jump through the hoops to become affiliate sales people, or simply give them a shortened link to use for your own affiliate sales.
Affiliate sales are iffy at best. Half the major distributors either barely support them or don't. Amazon is particularly picky, as they shut down whole states if they even threaten to tax online ebook sales. (While that's not rascist or sexist, it's still discrimination - but legal.) Of course your best revenge is to send people to those distributors who do offer affiliate sales. Just another reason to distribute to as many places as possible.
If you are going to give out a single affiliate link, it's best for you as a self-published author to use Leanpub. Because anyone who gets your book there will get the highest affiliate commission to reward their work. The buyer gets the most choices of ebook to download so it will fit on any ereader, smartphone, or tablet they have.
The other point of using affiliate links is to create another tracking point on how well your site is sending traffic.
Amazon is the simplest, if you are actually allowed to be an affiliate (and they don't cancel you capriciously.) But their payout is measly. I think I've gotten a (small) handful of $10 checks over the years before they cancelled Missouri.
For print books, you're basically screwed unless you're an Amazon associate. Lulu has no affiliate program right now. Next best is to send them to B&N to get a hardcopy.
There is concept of getting into a major bookseller and selling as an affiliate.
Powell's Books - https://www.powells.com/partners/partners.html - will give you your own bookshelf. http://www.powells.com/cgi-bin/partners/link_generate?type=isbnlink will give you individual links to your own books. Or you can use http://www.powells.com/cgi-bin/partners/partner-search for in-print versions. That is probably the preferable use for this. An actual bookstore which will ship actual books for your viewers. 7.5% commission. Better than Amazon.[http://www.powells.com/partners/partners_faq.html#commission1] They don't carry everything, though. (You can also get commissions for people selling their old hardcopy book to Powell's.)
Another approach is to sell your books as a wholesaler.
OverDrive - as a publisher, you can get your books into thousands of libraries, schools/universities, and retailers. I'm not ready to apply for this one, since I'm still in find-edit-publish mode. Once my backbench is established, I'll be able to take advantage of this. Once approved, you can then utilize OverDrive for digital titles, adding them as an additional distributor (this brings us up to 8 major distributors.) And so you have a further reach through more channels.
This does take you into the model of setting wholesale and retail pricing for your books, which may well wind up as overall lower royalties than using the other models, depending on your pricing model. But it will get you into places which Amazon, iTunes, and Nook don't always reach right now.
Obviously, anyone with more than a dozen titles and adding several per year should be on this service. Or - pool with other authors and select someone to manage your publishing for a fee (like 10% of profits) much as Lulu and the rest do. That person could also freelance in conversion services and find cover artists, editors, etc. In short, this is the route to becoming a 3rd-party services operation - much as selling picks and shovels to miners in this digital gold rush.
Obviously, OverDrive will take some more studies. They do match our premise for "publishing as many ways, in as many formats as possible" completely.
And then, there's Ingram's - who should be on your side, but is mostly just there for the money. (Their self-publishing arm is costly, with fees per each book - while Lulu has published for free for years, taking only 10% of whatever royalties you make through their distribution.)
For Ingram's, you essentially would set up your own online bookstore - like a publisher (http://www.ingramcontent.com/pages/online-retailers.aspx#WhatWeCarry, http://www.ingramcontent.com/Pages/Fulfillment.aspx) Practically, their monthly fees for getting access to their database isn't worth the cost of setting it up and running it - not for the simple Indie publisher.
Do you want to run your own affiliate program?The idea is that you should be able to simply give out links to people, or have them sign up to create their own links and market your book for you. The next step beyond that is to set up your book with digital delivery at an affiliate site such as Clickbank, and then get someone with a dropshipping service on a POD back-end. However, offering digital products is quite simple when you get the hang of it.
Running affiliate sites isn't the same as simply posting your book to distributors and letting the sales go while you tend to what marketing you can. However, if you are (and should be) converting your buyers to a mail list, then it's logical to include them in on special offers, giveaways, and pre-releases, etc.
While you already have an affiliate program in Leanpub, using Affiliate sites like PayDotCom, JVZoo, DigiResults, and Clickbank will enable you to take advantage of their distribution to hard-core affiliate marketers. Your existing audience will appreciate the commissions that Leanpub offers, but you can give the pro affiliate marketers up to 75% commissions using these others.
Frankly, running your own affiliate sales is a rabbit-hole for a different audience. What we are interested in is simply publishing your book in multiple formats (like to Lulu) and then get an affiliate link from the distributors so people (and you, the author) can make commissions back from selling your own book.
However, if you have just a handful of books, figuring out how to link the various Clickbank competitors to physical product fulfillment might be worth your while, given sufficient niche demand. This would be especially valuable to non-fiction writers using ebooks as an MVP (mimimal viable product.)
I recommend Indie writers-as-publishers take promote the Leanpub affiliate program to your current audience - as this is the best value and a minimal investment of your time.
Coming next in this series is how to set up your marketing for real with a membership. Almost no authors do this, and most Internet Marketers themselves don't know how to make it work. So stay tuned...