Delivering ads to Internet users via websites, e-mail, ad-supported software, text messaging and Internet-enabled cellphones. Also called an "ad network" or "ad serving network," Internet advertising organizations act as a middleman between the advertiser and the Internet venues that display the ads. They sell the online campaign to the advertisers and then deliver the ads to the sites that display them. The site owners receive a royalty based typically on the number of times users click the ads (see click-through rate). Such organizations may provide software tools that enable companies to deliver their own ads. See banner exchange, banner ad, Google AdWords and adserver.