They only offer $1 per ZiftrCOIN for the first 5% of each purchase, and only when using their shopping browser add-on. They state this explicitly on their website on "how the $1 redemption works" page.
Basically that is the rebate they get for their retailer network referral passed back to you.
It's a pyramid scheme to begin with layered with some GAW-like misleading quotes, marketing hype bonanza, and ripped-off clone coin that has already been exploited by pooled mining so that anybody with access to more than one PC can parallel process and dominate.
I rate this alongside the XPY 'ICO' debacle, only this time I think the price collapse.. to presumably 5% of $1.00 -- or about 0.000182 BTC based on current prices.