Years ago when attending lectures by a lactation consultant I had a little snigger when she said massaging your breasts increases available fats in the breastmilk at the beginning of the feed.
I pictured a milkshake.!
There have now been evidence based studies that show this is definitely the case . The fat globules stick to the sides of the ducts and massage encourages them into the stream of breastmilk injected when the feed commences.If you massage the breasts for 30 seconds before you feed you have a good idea of any problem areas and can change the position of the baby to maximise drainage of particular areas of concern.A bit like a quick breast check!