Many Web publishers utilize the services of third-party ad servers, often referred to as network advertisers. Network advertisers are third parties that attempt to target online advertising and make it more relevant to visitors based on Web traffic information collected over time across Web sites of others.("Network Advertisers").

Certain information practices of Network Advertisers are beyond the scope of the Online Privacy Alliance Guidelines and are being discussed in an industry sector specific forum, the Network Advertisers Initiative. With regard to the Online Privacy Alliance Guidelines, this statement considers the means by which Web publishers should address the use of the services of Network Advertisers in their online privacy policies.

Web publishers that use or permit the use of Network Advertisers should provide notice of all such Network Advertisers that collect information as a result of an individual's interaction with their site. Such notice should be incorporated into the Web publisher's posted policy and should include a means of contacting the Network Advertiser or a means of opting out of the disclosure of such information.

The Online Privacy Alliance Choice/Consent Guideline provides for choice to individuals of third-party distribution of individually identifiable information, collected online from the individual, unrelated to the purpose for which it was collected. In the context of Network Advertisers, if individually identifiable information collected by a publisher will be transferred to and used by Network Advertisers, this should be disclosed in the publisher's notice with the opportunity for individuals to opt out of such transfer and use. Additionally, Web publishers should provide individuals with notice and an opportunity to opt out prior to transfer or use of individually identifiable information to a Network Advertiser if such use or transfer was not disclosed in the notice at the time of collection.