Definition: Out of total purchases of a customer of a product or service, what percentage goes to a company defines its market share. In other words, if consumers as a whole buy 100 soaps, and 40 of which are from one company, that company holds 40% market share.

Description: There are various types of market share. Market shares can be value or volume. Value market share is based on the total share of a company out of total segment sales. Volumes refer to the actual numbers of units that a company sells out of total units sold in the market. The value-volume market share equation is not usually linear: a unit may have high value and low numbers, which means that value market share may be high, but volumes share may be low. In industries like FMCG, where the products are low value, high volume and there are lots of freebies, comparing value market share is the norm.

The significance of market share: Market share is a measure of the consumers' preference for a product over other similar products. A higher market share usually means greater sales, lesser effort to sell more and a strong barrier to entry for other competitors. A higher market share also means that if the market expands, the leader gains more than the others. By the same token, a market leader - as defined by its market share - also has to expand the market, for its own growth.

How much market share is enough? Usually, gaining 100% market share is not a good idea, as the risk associated with market actions, like fashion changes, product / use changes will impact the company heavily. Also, the cost and effort to maintain 100% market share against nimble, local or more aggressive smaller competitors can be very high and killing. Most companies decide on a target market share beyond which the cost of acquiring marketshare is more than the profit from that incremental gain.