This document provides an introduction to interactive media and Web 2.0. It discusses how Web 2.0 sites generate revenue from online advertising and lists popular sites like Facebook, YouTube, and Wikipedia. It also describes Forrester Research's Social Technographics Ladder, which segments users into categories like Creators, Critics, Collectors, and Joiners based on their level of participation in social media. Examples of using different online advertising approaches like search engine marketing, display ads, and social media for brands are provided. The concept of online "tribes" or communities is introduced at the end.