A method for operating a host through which clients may obtain content from different services, wherein the host stores information about which service invoked which other services, the method comprising the computer-implemented steps of: receiving, at the host from a client that is remotely located relative to the host, a first request for content from a first service; in response to receiving the first request, the host sending a second request to the first service for the content and retrieving first content from said first service, wherein the first content contains a reference to a second service that is different than the first service; prior to delivering the first content to the client, the host locating within the first content the reference to the second service; the host generating a first reply; and the host providing the first reply to the client in response to said first request, (a) wherein said first reply includes, based on said reference, an object that is selectable by a user of said client, and further comprising: said host, in response to selection of said object by said user of said client, causing invocation of a programming routine of said second service, resulting in said host receiving second content from said second service; and said host providing a second reply that includes the second content to said client in response to said selection of said object by said user of said client, or (b) wherein said reference is a reference to second content from said second service, and further comprising: the host, based on said reference, causing invocation of a programming routine of said second service resulting in said host receiving said second content from said second service, wherein said first reply includes said first content into which the host has embedded said second content. receiving, at the host from a client that is remotely located relative to the host, a first request for content from a first service; in response to receiving the first request, the host sending a second request to the first service for the content and retrieving first content from said first service, wherein the first content contains a reference to a second service that is different than the first service; prior to delivering the first content to the client, the host locating within the first content the reference to the second service; the host generating a first reply; and the host providing the first reply to the client in response to said first request, (a) wherein said first reply includes, based on said reference, an object that is selectable by a user of said client, and further comprising: said host, in response to selection of said object by said user of said client, causing invocation of a programming routine of said second service, resulting in said host receiving second content from said second service; and said host providing a second reply that includes the second content to said client in response to said selection of said object by said user of said client, or (b) wherein said reference is a reference to second content from said second service, and further comprising: the host, based on said reference, causing invocation of a programming routine of said second service resulting in said host receiving said second content from said second service, wherein said first reply includes said first content into which the host has embedded said second content. (a) wherein said first reply includes, based on said reference, an object that is selectable by a user of said client, and further comprising: said host, in response to selection of said object by said user of said client, causing invocation of a programming routine of said second service, resulting in said host receiving second content from said second service; and said host providing a second reply that includes the second content to said client in response to said selection of said object by said user of said client, or said host, in response to selection of said object by said user of said client, causing invocation of a programming routine of said second service, resulting in said host receiving second content from said second service; and said host providing a second reply that includes the second content to said client in response to said selection of said object by said user of said client, (b) wherein said reference is a reference to second content from said second service, and further comprising: the host, based on said reference, causing invocation of a programming routine of said second service resulting in said host receiving said second content from said second service, wherein said first reply includes said first content into which the host has embedded said second content. the host, based on said reference, causing invocation of a programming routine of said second service resulting in said host receiving said second content from said second service, wherein said first reply includes said first content into which the host has embedded said second content.