I live my life with a fair bit of intensity, quite a bit of dedication to that world I live in and it is not one which many could keep up with.
Thankfully, I only work at marketing about 25 hours a week, which is the same time I have for writing and editing. So this keeps the amount of work I would bite off for myself small enough to chew for the most part.
Practically, were this making money, I'd hire someone to keep up with all the books I could create. Certainly I now have the basic skeleton down of how to do it.
But, alas, I am a sole entrepreneur, not having broke through that glass ceiling of the ignorance I've had for so long. And so the need for testing. I do make money on book sales, but not enough to make it hardly support the marketing research required. So it is just me and my able keyboard fingers working away during my too-short weeks.
I've many, many books on the back-burner. And they are going to stay there until I get mostly caught up with all my marketing work.
This marketing work continues, and I also have started to get my own schedule based on needing a day of recovery after my weekend day-job.
So I don't expect a great deal of people to try to compete with me on sheer output. However, they can just be effective and efficient in their own right and they'll do just fine.