Earlier quoted context omitted.
Specifying technical books is interesting - my first book was fairly technical (though the spiritual theme which probably reduced the target market significantly) but my most successful books monetarily were far and away the erotica I wrote primarily for my own gratification. I know erotica's an active genre, but it's still a source of consternation that I get so much more reader interest for something so much easier…
Having written erotica on the side while working a day job where I write technical content, I truthfully find it much more difficult to write erotica. :P Props to you for doing it skillfully enough to get paid!
I wish I knew whether I was actually better at erotica than other genres or people are just more likely to pay for erotica. I suspect it's the latter...