yea of course - loyalty cards are the forefront of huge data mining operations for the likes of tesco, asda et all
using facts such as people generally shop at the same time (be that weekly, monthly, etc) and generally purchase the same items (outside of promotions) these companies can pre-order stock based on these trends and use targeted promotions to drive trade.
but i think that is outside the scope of this thread
My GF always asks me "why are they sending me vouchers for Whiskers when we never buy that cat food?".
I tell her that's the point...