Anyone ever heard of Shoppers Hotline - Information Resources Inc.? We were asked to participate as a Shoppers Hotline Panelist. They provide panelists with a ScanKey to scan all your purchases and transmit data once a week.
Not sure if it was the same company, but I did it once (don't remember the companies name) They sent me a scanner, I had to scan everything I bought, then look at my receipt and enter the price... then I had to total my shopping trip (enter how much I spent each trip etc) It had to have access to a phone line and would then send it in to the company. It was a lot of work, and I didn't get any 'reward'. No money or coupons etc... It was just too much trouble for us.
