There is a foremilk / hindmilk imbalance in your make because you either have a too fast letdown, you have an oversupply of milk, or you switch boobs far too often. (momwoot.com)
I've got a super fast letdown and after the initial rush of milk she doesn't like to work for the rest. (babywisemom.com)
The same goes for faster letdown and increased milk flow. (rachelsremedy.com)