What's the 'rather specific market theory'? As far as I understand that is the dictionary definition of a market. Here's Meriam-webster:
market, noun, often attributive
mar· ket | \ ˈmär-kət \
Definition of market (Entry 1 of 2)
1.
a(1) : a meeting together of people for the purpose of trade by private purchase and sale and usually not by auction
(2) : the people assembled at such a meeting
b(1) : a public place where a market is held
especially : a place where provisions are sold at wholesale
a farmers' market
(2) : a retail establishment usually of a specified kind
a fish market
2. archaic : the act or an instance of buying and selling
3. : the rate or price offered for a commodity or security
4.
a(1) : a geographic area of demand for commodities or services
(2) : a specified category of potential buyers
the youth market
b : the course of commercial activity by which the exchange of commodities is effected : extent of demand
the market is dull
c(1) : an opportunity for selling
(2) : the available supply of or potential demand for specified goods or services
the labor market
d : the area of economic activity in which buyers and sellers come together and the forces of supply and demand affect prices