On-line advertising and marketing services; On-line advertising on computer communication networks; On-line trading services in which seller posts products to be auctioned and bidding is done via the Internet; Promoting the goods and services of others via a global computer network; Providing a web site that enables users to post items for sale through on-line classified advertisements; Providing a web site which features advertisements for the goods and services of others on a global computer network; Providing space at a web site for the advertisement of the goods and services of others