My publisher also provided most of the above (extensive copyediting, developmental editing, and technical review). Given how niche the market is, I'm quite happy with sales so far. As far as marketing goes, it's hard for me to tell as an author how extensive the support has been.

I guess you're selling so many copies of each book (and based on your watchwords) by being quite selective about what titles you publish?

For the record, I do think my book is great but writing a book is not black and white - it's such a big endeavor that there is generally more than one motivation. I also didn't want to self call.