Sleeping through the night and breastfeeding correlation

I randomly thought about this the other day and I wonder if this idea is of any significance. I noticed that mothers of babies who sleep through the night early on (sleeping longer than 6-8 hour stretches, in this case) are less likely to nurse their babies past the half-year mark. It's just that whoever I talk to whose babies were such good sleepers as newborns and young infants said they didn't nurse beyond a few months.

Here's why I think that happens. It's widely known that milk production gets a real boost during the nighttime when prolactin, the milk-making hormone, is at its best. Nursing (or even pumping) at night really gives your milk supply an edge even beyond the nighttime. Now, if a mothers isn't breastfeeding her baby at night because the child sleeps through the night (and why wake a sleeping baby?) her prolactin doesn't really get chance to shine.

If milk supply isn't given that extra oomph from nighttime nursing, it might not function so well during the day. This is even more hampered if a mother works full time and has to rely on pumping during the day to keep up her milk supply. If a mother can stay at home with her child and nurse on demand then this probably isn't such an issue because a nursing baby can effectively extract enough milk (whereas a pump doesn't do that great of a job).

Now this is far from a scientific fact; it's just a speculation on my part. What do you think? Do you have evidence to support or disprove this claim? If yes, share it! I will try to conduct a poll about this on a breastfeeding website and share the results here.