Commercial refrigerators refer to those refrigerators found in stores, bakeries, hypermarkets, and factories. Currently, most commercial refrigerators are �dumb�, and their main functionality is only limited to keeping food fresh. Helping fridge manufacturers by enabling those refrigerators intelligent to identify products taken in/out and facilitate the process of purchase without the need of shopkeepers can surely bring a significant breakthrough in the retail industry. Not only the cost of hiring can be reduced, but the efficiency can be improved tremendously especially on purchasing perishable items such as fruits, cooked food, vegetable and so on. The ability to operate 24 hours per day could bring convenience to people who might need to buy perishable items at midnight. Most importantly, the improved computing power and advancement of computer vision technology makes the realization of this idea possible.