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In marketing jargon, product lining is offering several related products for sale individually. Unlike product bundling, where several products are combined into one group, which is then offered for sale as a unit, product lining involves offering the products for sale separately. A line can comprise related products of various sizes, types, colors, qualities, or prices. Line depth refers to the number of subcategories a category has. Line consistency refers to how closely related the products that make up the line are. Line vulnerability refers to the percentage of sales or profits that are derived from only a few products in the line.
The number of different categories of a company is referred to as width of product mix. The total number of products sold in all lines is referred to as length of product mix. If a line of products is sold with the same brand name, this is referred to as family branding. When you add a new product to a line, it is referred to as a line extension. When you have a single saleable item distinguishable by size, appearance, prize or some other attribute in your product line, it is called SKU-Stock Keeping Unit.
The marketing jargon for adding a product that is better quality than other products in the line is trading up or brand leveraging or up-market stretch. A line extension of lower quality is called trading down or down-market stretch. Trading down may reduce your brand equity by gaining short-term sales at the expense of long term sales. The jargon for "stretching the line" in both the directions is "two-way stretch".
Image anchors are highly promoted products within a line that define the image of the whole line. Image anchors are usually from the higher end of the line's range. When you add a new product within the current range of an incomplete line, this is referred to as line filling.
Price lining is the use of a limited number of prices for all your product offerings. This is a tradition started in the old five and dime stores in which everything cost either 5 or 10 cents. Its underlying rationale is that these amounts are seen as suitable price points for a whole range of products by prospective customers. It has the advantage of ease of administering, but the disadvantage of inflexibility, particularly in times of inflation or unstable prices.