Unlike black market goods, grey-market goods are legal. However, they are sold outside normal distribution channels by companies which may have no relationship with the producer of the goods. Frequently this form of parallel import occurs when the price of an item is significantly higher in one country than another. This situation commonly occurs with electronic equipment such as cameras. Entrepreneurs buy the product where it is available cheaply, often at retail but sometimes at wholesale, and import it legally to the target market. They then sell it at a price high enough to provide a profit but under the normal market price. International efforts to promote free trade, including reduced tariffs and harmonized national standards, facilitate this form of arbitrage whenever manufacturers attempt to preserve highly disparate pricing. Because of the nature of grey markets, it is difficult or impossible to track the precise numbers of grey-market sales. Grey-market goods are often new, but some grey market goods are used goods. A market in used goods is sometimes nicknamed a Green Market.
The parties most concerned with the grey market are usually the authorized agents or importers, or the retailers of the item in the target market. Often this is the national subsidiary of the manufacturer, or a related company. In response to the resultant damage to their profits and reputation, manufacturers and their official distribution chain will often seek to restrict the grey market. Such responses can breach competition law, particularly in the European Union. Manufacturers or their licensees often seek to enforce trademark or other intellectual-property rights against the grey market. Such rights may be exercised against the import, sale and/or advertisement of