There is no personal benefit to anyone shopping on someone else's website. Let's face it, people are inherently lazy and barely to things when they personally benefit! They aren't going to do it!
But...if YOU join and shop on your OWN website, you will save the cash back percentage in addition to any coupons you already have. Additionally, you will be able to share in the loyalty points the retailers give when you DO shop and save.
Basically, STE goes to a retailer and offers to point 60,000 shoppers to their website if they offer a discount. They offer a discount because we are their personal advertisers so they are willing to "pay" for that. They are assured that we will continue shopping with these retailers because, besides the cash back, you receive POINTS for your purchases and those points go to YOU and all of the people ABOVE you. The points then cash in for $$$
That's network marketing. It's a great model because you're earning cash back on things you were already buying! There are lots of articles about how e-commerce is the wave of the future. The most recent one was in USA Today entitled Retailers count on Web appeal for holiday shopping by Jane O'Donnell.
Hope that helps.
:-D