LexisNexis Academic Universe contains full-text coverage of many newspapers and trade journals, including current issues of Variety and Broadcasting and Cable. Feel free to ask for help setting up search parameters.
Factiva has a wealth of business-related coverage, including the media and entertainment industries. It also has extensive full-text access from The Wall Street Journal.
Entertainment Industry Magazine Archive contains full runs of key trade and consumer magazines in film, broadcasting, popular music and theater, including Variety and Billboard. It contains full color page reproductions and full-text search capability, including within ads. Coverage: varies by title, ends at 2000.
The Media History Digital Library also includes searchable, full-text access to many entertainment industry trade publications, including broadcasting titles such as The Radio Annual and Television Yearbook.
American Radio History offers access many full-text industry magazines, among them the Broadcasting Yearbook. This yearbook includes detailed information such as station ownership within local radio and television markets.