"market share   The share of the total sales of all brands or products competing in the same market that is captured by one particular brand or product, usually expressed as a percentage. For example, if brands A, B, and C are the competing brands of a product and in a particular month they achieved sales of £480,000, £620,000, and £900,000, respectively, brand A's market share would be

   (480,000/(480,000 + 620,000 + 900,000)) × 100 = 24%."

Market Share.  (2009) In J. Law (ED) A Dictionary of Business and Management. Oxford: Oxford University Press,  Retrieved from 

"Market Share This is the ratio of a company's sales of a product or services (either by number of units or by value) during a specific time period in a specific market to the total sales of that type of product or service over the same period.  It has been pointed out that calculations of market share are likely to vary considerably according to how the total market is defined.

The importance of market share has frequently been noted with, for example, a connection between market share and profitability identified in a project undertaken by the Marketing Science Institute on the PROFIT IMPACT OF MARKET SHARE.  Other researchers...have suggested that the direc timpact of market share or profitability, while not unimportant, is substantially less than is commonly assumed.  Jacobsen & Aaker express concern that efforts to maintain or increase market share by companies can be myopic, expensive and detrimental to long term profitability, and note that one of the premises of niche marketing is that smaller market share competitors... can also achieve high returns."

Leverick, F (1999) Market Share.  In B.R. Lewis (ED) Blackwell Encyclopedic Dictionary of Marketing (pp. 117-118) Oxford:  Blackewll Publishers.  Retrieved from NetLibrary.

Terms closely related to "market share" more often used by economists include concentration and market structure.  See the New Palgrave Dictionary of Economics for defintions.

Sources for Market Share at Falvey Memorial Library

Finding market share for product or brand XY or Z takes a good deal of thought since the market is defined by keeping geographic, temporal and product or brand characteristics and parameters in mind.   The only way to find market share for your target market may be to compile it yourself by identifying the the players in your market and calculating  their share.  However the following resources report market share for various product and brands as defined by other researchers.

Market Share Reporter  This is an index to market shares published in trade, professional, news and research reports.  It should be the first place to look for market share, but not the last.

Marketing Reports

  • Global Market Information Database (Euromonitor)  Market share reported in industry reports and via statistical tables.  Use the Search Brands feature or search by Service, Industrial or Consumer markets to locate company and brand shares.
  • Datamonitor Industry reports (not company) typically report market share by value for companies (not brands).  Access Datamonitor Industry reports via ReferenceUSA OneSource (international).
  • Business Monitor International Reports Market share if often but not consistently included in these reports that tend to cover Asian markets.  Access BMI reports via ReferenceUSA OneSource (international)
  • Mintel Reports  Brand share, segment and channel shares are typically included in these U.S. and international market reports.
  • Academic  Aggregator for market reports by Packaged Facts, Kalorama, Simba International, and others typically reports on market share by catagory and/or brand.

Don't forget to check the Marketing Subject page for additional specialized market research reports such as those that appear in Gartner for technology and Sports Business Research Network.

Trade Publications

  • Business & Industry Advanced Search, In Concept Term dropdown choose market share.
  • ABI/Trade & Industry Advanced Search enter target in first search box AND "market shares" in second search box.
  • Business Source Premier Advances search enter target brand or product in first search box AND "market share" in second search box.
  • Lexis/Nexis From the News search tab, choose Business News Publications as Source, adjust the date to previous 2 years, in search box type"target brand or product w/s market share".
  • Business Full Text  Type the target product, company or brand in the first search box AND market share in the second search box.  Focus search by using drop down menu to select Subjects(s) only search for market share.

Another Alternative

MRI+University Internet Reporter provides market share by volume and users (but not sales).  Choose the Product database, and choose "View Summary" from the uppermost bar. MRI+ only works with Internet Explorer.  MediaMark data may be used for ACADEMIC TEACHING PURPOSES only.  Our license agreement prohibits quotatons of MediaMark data in any publication.