Billa, a retail store in Romania created the first Social Catalogue - a catalogue in which Billa Facebook users decided the discount value of the products with a simple Like. Each day a new product was published in the Catalogue Facebook App and simultaneously in a post on Billa Facebook Wall. 

People were invited to Like the product if they were interested in purchasing it with a discount. According to the number of Likes reached in 24 hours, the product could be bought in Billa stores, in the entire country, with a discount up to 50%. The value of the discount was directly proportional to the number of Likes gathered