Working to a target, meaning daily wordage targets, gets books written faster and probably better. Personally I love them because they make my writing life simple. I sit down each day knowing what I have to do, in what time, and what the final outcome will be over time: a completed project by a certain date. Simple. The maths is easy. A thousand words a day will get a novel finished in about 3 months. 500 words a day makes it six months to completion. 2000 words a day… well you can work it out. Without my daily target I drift. Days become weeks and soon months of unhappy, uneasy, limited output.
Your target will be different than mine. If you’ve not already got a clear, workable one, then make a decision to write each day for a month and see what your daily average is in terms of wordage. Calibrate the next month to that and see how you get on. You’ll soon know what you’re comfortable with. You’re likely to find that anything under 300 words a day doesn’t work because it’s not enough to get ideas and words flowing. More than about 2500 over a period of more than a fortnight may well lead to creative fatigue. It does for me. But I often do more for a short period, sometimes because the work is flowing, but also just for the hell of it. Incidentally, the reason many internet writers churn out a lot of books is because their books are very short – maybe only 15,000 words long. If the idea’s simple and you’ve got it clearly worked out, you can do that kind of wordage in four or five days. But what you’re aiming to work out is your sustainable daily average over three months. Work to that consistently and you’ll get your book written.