My triple dip is the following:
- AMEX at Shoppers for Shoppers GC (to get Shoppers points)
- Shoppers GC for Non-Shoppers GC at Shoppers (no points)
- use those GC that get points/miles at those stores (i.e. ESSO, Starbucks, etc...)
BTW, just want to state that you will still get Shoppers points for using the Shoppers GC at Shoppers to buy stuff that normally earn Shoppers points. So that it's is double-dipping within Shoppers already, adding the AMEX to get the Shoppers GC at first, that is also triple dipping.