I spent much of a year writing this kind of thing (around 1994 or so?), but I didn’t work nearly this much at it — writing a 9000 word novella paid $900, and writing two letters for the front of the magazine paid $300 each, and that basically took two days of the month and covered rent.
It was an interesting gig at first — I did erotic versions of Thomas the Rhymer, a zeppelin murder mystery, and more. The magazine even illustrated them! Eventually, I got too bored with their formula of a sex scene every 1000 words — it was as dull as tech writing, and I couldn’t bring myself to keep doing it. Good money while it lasted, though.
I periodically think about reissuing those novellas as ebooks, but I admit, I feel a little weird about it. Not for any good reason, though — am I getting conservative in my old age? Maybe if my dad (and his friends) promise not to read them…