Zedo (trademark styled as ZEDO) is a privately held company founded in 1999 by Roy de Souza, which provides several online advertising products and services to Internet publishers, advertisers, and agencies. The company works with publishers who sell space on their web pages to online advertisers. Zedo’s servers send advertisements to users’ browsers. Zedo uses an HTTP cookie to track users’ browsing history resulting in targeted pop-up ad and pop-under ads. The cookie is often flagged by spyware and adware removal programs. In a 2013 case study written by Amazon, Amazon described ZEDO as a company that develops innovative technology solutions to help publishers sell and deliver Internet ads.