a prototype logo based on Paramount's mountain logo, which served as the basis for the "P" triangle in the network's original logo that was used until September 2002. This idea was abandoned after many affiliates protested, citing that the rebranding might confuse viewers and result in ratings declines, alongside the costs of rebranding their stations with a new image and new network (and possible call sign changes). Several years later, cable television network Spike (part of Viacom) re-branded as Paramount Network. Viacom's purchase of CBS a few months before (which resulted in the merger of that network's owned-and-operated stations into Viacom's Paramount Stations Group unit), created duopolies between CBS and UPN stations in Philadelphia (KYW-TV and WPSG), Boston (WBZ-TV and WSBK-TV), Miami (WFOR-TV and WBFS-TV), Dallas–Fort Worth (KTVT and KTXA), Detroit (WWJ-TV and WKBD-TV), and Pittsburgh (KDKA-TV and WNPA). Viacom's purchase of CBS was said to be the "death knell" for the Federal Communications Commission's longtime ban on television station duopolies. Further transactions added San Francisco (KPIX-TV and KBHK, the latter of which was traded to Viacom/CBS by Fox Television Stations) and Sacramento (KOVR and KMAX-TV, the former of which was sold to Viacom/CBS by the Sinclair Broadcast Group) to the mix. At the time of UPN's launch, the network's de jure flagship stations were Chris-Craft-owned WWOR-TV in Secaucus, New Jersey (which serves the New York City market) and KCOP-TV in Los Angeles (which serves the Los Angeles market). Even after Chris-Craft sold its share in the network to Viacom, WWOR and KCOP were still commonly regarded as the de jure flagship stations of the network since it had long been common practice for this status to be associated with a network's station in the East Coast and West Coast. For this reason, some doubt was cast on UPN's future after Fox Television Stations bought most of Chris-Craft's television stations for $5.5 billion on August 12, 2000, which included several UPN affiliates (including WWOR and KCOP). Fox later bought the third-largest UPN affiliate, Chicago's WPWR-TV, through a separate deal with Newsweb Corporation for $450 million in June 2002. Despite the uncertainty of the network's future following the Fox purchases, UPN reached four-year affiliation agreements with Fox Television Stations' nine UPN affiliates on September 24, 2003. In 2001, UPN entered into a public bidding war to acquire two series from The WB – Buffy the Vampire Slayer and Roswell – from