A community center compared two ways of announcing free evening classes. Printed posters reached people who visited the building regularly, while text messages reached some residents who rarely entered it. Neither method reached everyone. Posters remained visible for weeks but could not adapt when a room changed. Messages could be updated quickly, but several residents had shared phones or changed numbers. The center concluded that communication channels should be judged by both reach and adaptability. It kept posters for stable information and used messages for changes that required a quick response. The result was not a declaration that one channel was superior. It was a division of roles based on the conditions under which each channel worked. A summary that mentions only reach would miss why the center retained two methods, while a summary that mentions only speed would ignore who could actually receive the information.