Shell offers .05 a gallon discount with signup to their program. It tracks your receipts to provide additional bonuses or keep you at .05 less. You use your phone number as the Alt ID. What they dont tell you - and what is nowhere in the set up - you have to set a pin. You then enter your phone + pin to access. The attendant was useless and calling to CS a nightmare in menus! I went to BJs instead and paid less! User's recommendation: Think twice- especially with rising gas prices. Go to where doing business is easy!