Portable People Meter measurement captures 'real' radio cume build, rather than current estimates based on weeklong diary surveys, modeled over multiple weeks. Early PPM results in the Philadelphia (US) market confirm previous benchmark industry studies. Decades-old research indicated that 'real' multi-week reach was roughly twice that of single-week modeled data. PPM cumes for 34 stations averaged over 200% higher than modeled diary curves. The vast majority of the PPM "gain" occurred over the first week of measurement rather than spread equally over successive weeks. Enormous station-to-station variation in the PPM cume build contribution, both overall and within format groupings, existed. First results indicate that broad-target music formats (e.g. Classic Rock) gain more cume build than narrower targeted formats such as Talk Radio and Urban Contemporary Music. Although too early for actionable recommendations, results imply that current reach and frequency models are overly general and conservative. If the industry accepts PPM measurement and PPM expands to larger samples and more markets, this method will provide a solid basis for correcting current industry models.