As a friend shared with my recently...ignore your heavy users and they will spank you like you are a 5 year-old in Wal-Mart.
The point is, focus on your core users, your brand fans. If you really know them then you know what to do for them at the shelf or at the mouse or at the mobile. And if you don't know...it is time to go back over your data or get new data. I also believe every brand should have a life-size mock up of their brand fans in conspicuous locations so employees learn and remember who they serve.