This document outlines the Network Advertising Initiative's (NAI) self-regulatory code of conduct for 2008. It discusses how online advertising underwrites free and low-cost content on the internet. It also describes how the NAI was originally formed in 2000 to establish principles guiding online behavioral advertising services and how the code has been revised over time as new advertising models have emerged. The code aims to balance effective advertising with consumer privacy through self-regulation and by addressing issues like notice, choice, data use limitations, access, reliability, and security.