I have used them. I wouldn't say they "suck" but I'm not a big fan. They work a bit differently than others like ShopSense. RewardStyle pays you the actual commissions on your sales and because of the potential for returns you won't see any money for the first 3-6 months. This is really irksome for me because I like to figure out how much revenue I earned at the end of each month, and April's revenue will keep changing for months afterwards.