Well, I know Best Buy does this, and has for quite some time. They've tied my offline and online purchase history together with my Best Buy Rewards Zone card. They throw away orders that are too old? But I have an online order in my system as old as November 2011.
"LEGO VIP Program
If you are 13 years or older (age limitation may vary by country), you can join our LEGO VIP Program in physical LEGO Brand Retail Stores, online via LEGO Shop at Home, by phone via the LEGO Consumer Services Center, or through LEGO events offered by the VIP program. If you sign up ...