A network system provides delivery of customized target content, such as advertising, to individual users. There is transmission of a common spot content stream to a large group of the users. Each home client user communicates through a telecommunications network, such as the Internet, for connection to a portal to receive continuing media, such as streaming audio or video. The user installs receiver software at his home client processor for receiving both the streaming media and a content stream. The media stream includes spot markers placed at appropriate locations in the media stream by the publisher to designate locations for insertion of spot content and optionally to identify specific characteristics of the media stream. The content stream includes content units, such as audio advertising, together with spot content frames, which include parameters having values designated by the spot content provider to be the target audience. A profile is produced at the home client having parameters with values associated with the home client user, such as geographic and demographic information. The receiver software at the home client matches the spot content frame for each spot content to the profile of the user to select those spot content units which have a match. These selected spot content units are stored at the home user and are blended into the media stream at the locations of the spot markers to produce an information data stream for the user that is customized for that user. A spot auditor at the home client measures the type and quantity of play back of the spot content received by the home user and this is reported to the spot content provider for measurement of the effectiveness in the distribution of the spot content.