I still remember when it first came out, it was such a big hit and everyone was using it. I remember going to Kmart Auto to get my tyres because of some FB promo. Overall I got a trip or two and a nice dinner at the tramcar restaurant from it, but has since switched to Amex/Visa for points in QF/SQ.
I think it is fading away right now - given the popularity of credit card-based loyalty program is such much more convenient (earn points at all stores and not a separate card). Although I still carry the card around, I never take it out anymore.
The only future I see it is similar to the MyerOne card, where the points are automatically converted to giftcards and send to you on a periodical basis.