Spectrum's UK public call boxes offer advertisers an ideal medium for poster-based campaigns. Typically Spectrum's call boxes are located in areas of high footfall and give potential advertisers the ability to create high awareness levels through the site.

Past and present advertisers include Sainsbury's, eSure, Waitrose, KFC, Virgin and Ford.

Approximately 25% of Spectrum's 2000 street sites in the UK permanently display long-term advertising, with the remainder regularly booked by leading agencies for the display of their own clients' short-term campaigns.