I hope you and Kos kept the rights to the "special sales" of your book. Normally, the publisher (who is it, anyway?) will hold exclusive rights to selling books to the "trade" -- ie, retailers who sell books as a major part of their business. Everything else is called a "special sale," and the terms are completely negotiable. (though the publishers try to keep everything they can.) You two will be able to sell quite a number of books over the internet--maybe more than your publisher will sell through more conventional outlets. And since you're doing the selling yourselves, with no assistance from the publisher, you're entitled to...well, whatever you can get. If you kept the "special sales" rights, you could do a special edition of the book to sell over the internet. That would be fairly easy, and enormously profitable for you. Or you could negotiate a bigger percentage of the take. If you wind up selling books at retail over the net, and buying them wholesale from the publisher, negotiate a non-returnable bulk sales price. Don't let them sell you books at the normal 40%-50% discount; the price they pay for printing books is amazingly low, and they can still make plenty of money by giving you at least 60% off the retail price.
     If you have questions about how to navigate the publishing industry, I'll be glad to answer them. But frankly, there are dozens of small publishers in Berkeley, and any of them would be glad to help progressives of your stature.
    If the book is good (as I hope it will be), it will sell very, very well. I look forward to reading it.