"Network affiliates" refers to television stations or radio stations that are part of a larger broadcasting network. These stations have agreed to broadcast the network's programs and shows to their local audience. Full definition
They can also send encouraging messages and whatever else they'd like through a private social network affiliated with the challenge. (gigaom.com)
The person got fired for this tweet, maybe because one was working for huge television network affiliate. (resumewritingservice.biz)
NOTE: The drop in number of stations in 1977 is attributed primarily to substitution of these programs with paid - time religious programs by network affiliates. (religion-online.org)