About Newsletter Swap
Just about every successful self-published author has their own newsletter mailing list, where they ask their readers to sign up, and the readers then get access to new releases, ARCs, freebies and various other goodies from the author.
And one of the things that many readers (98.2% to be exact!) like to get from their favorite author is a book recommendation. Just about all authors are readers too, afterall, and a lot of them have good taste... or like to think so anyway :)
Newsletter Swap is a system whereby authors can find other authors in their genre who also have a newsletter mailing list full of readers, and they can then exchange book recommendations. You recommend my book to your readers, I'll recommend your book to my readers. After all, if you have a month between book launches, for example, it's smart to send your readers some kind of email, just so they don't forget about you. Why not a book recommendation email?
But it goes way beyond that too. You might find 5 different authors that are willing to recommend your book, and those authors might send a book promotion request to you in turn... or they might go ask any one of a number of other authors to recommend their book to readers.
What Newsletter Swap does that enables this kind of sharing to work is we record every click that comes in from reader newsletters. That way, there's a record of how many clicks you have received from other authors, as well as how many clicks you have provided to other authors. As long as the ratio between those two numbers isn't too out of whack, everyone knows that you're a contributing member of the Newsletter Swap community, and you're someone worth working with.
Of course, you're under no obligation to promote other author's books. If you're going to recommend a book to your readers you should make sure that it's something you enjoy, and that your readers will enjoy. So every time an author sends a request to promote a book to you, you have the option of accepting or rejecting their request.
And that's how Newsletter Swap works. It's just authors helping authors get their books out to hungry readers.