Many responses to respond to here. Victoria, the beer was excellent, Harpoon IPA, and thanks!
(Yours is also the kind of success story of this type of interaction that I love to hear.)
There's no doubt that the absence of the first three books in new editions hurt sales of the new book, which was #4 of a series. But as I said, I couldn't move Tor to reissue, which was what prompted me to put up the first three as free ebooks in the first place. I had never intended to make Sunborn a free ebook indefinitely, and was going to pull it (except for PDF) as soon as Tor made their ebook version available. But I wanted people to be able to
get it as an ebook, and I preferred giving it to having it unavailable. Then Tor took more than a year to get their ebook out, so although I have now removed all except PDF and HTML versions from the free page, that barn door is pretty saggy at this point.
Dadioflex and K-Thom mentioned print on demand as a possibility. In fact, some of my other backlist books
are now available as POD,
from ereads. These are titles that have been reverted from the original publishers. They're nice trade-paperback editions. But they're also a little pricey--$15-20, depending on size--and that's the problem with POD. It's still too expensive to appeal to the mass market, and so far, they don't sell very well at all. As far as I know, none of the big publishers are doing much with POD, probably for that very reason.
As far as promotion for the book, I did extensive online promotion, but relatively little in-person promotion. (I was in the middle of a family crisis when the paperback came out, and that hampered everything related to promotion. I didn't even notice the pub date had come until it was already gone.) But "signing tour"? No, that's one of those things that people think all authors do, on their publishers' dimes. It doesn't work that way. It doesn't pay, for any except the already bestselling author. Most of us do signings when and where we can, but we know that payback is limited. (Although I did do one really great signing for Sunborn--in my local beer and wine store, during a wine tasting! Best signing ever.)
My editor thinks distribution was the biggest factor against me. I think the lack of the earlier books in print was the biggest.
I have no regrets about offering the downloads. That gained me a lot of new readers among the ebook audience. But the hoped-for carryover to the treebook audience is what failed to materialize. (I think Mr. Ploppy has it right.)