: , , . " " " ", , .
: , , , , , , . " " , " ", .
-, : , / ( / ) -.
:
- - (B2C, business-to-customer) -;
- (B2B, business-to-business) ;
- (B2G, business-to-government). .
(online catalog) - , . , , , , , , , .. , , - IT-. , .
(auction) - , , . , .
(exchange) - -, , . , , , , . .
(ommunity) - - . , , , , , . , . - , , .