In FY 2009, TV and radio station grantees reported to CPB (on their Annual Financial Reports) a total of 5.6 million individual contributors (either to stations or to their associated “Friends” groups). There is undoubtedly some double-counting of individuals in that number (because some individuals give to more than one station), but CPB has no way of “de-duping” these data.
In validating a rule-of-thumb such as “only about one listener in 10 is a member/contributor,” it makes a big difference whom you count as a “listener” — anyone, for example, who listens at least once a month?… or only someone who listens at least once a week?
Public radio’s weekly cume audience is about 30.6 million persons, so the roughly 2.5 million contributors reported by public radio stations would be about 8 percent of the weekly cume listeners (roughly 1 in 12). Its monthly cume audience is estimated at about 64.7 million persons, so the reported contributors would represent about 4 percent of the monthly cume listeners (about 1 in 25).
Similarly, public television’s weekly cume audience is about 60.4 million persons, so the roughly 3.2 million contributors reported by public TV stations would be about 5 percent of the weekly cume viewers (1 in 20). And public TV’s monthly cume audience is about 121.9 million persons, so the reported contributors would constitute about 2.6 percent of the monthly cume audience (1 in 40).
Of course, the “unit of giving” is often a family or household, and the “units of listening or viewing” I just cited are individual persons (aged 12+ in the case of radio, or 2+ in the case of TV), so these ratios shouldn’t be considered very precise or reliable… but then neither are most “rules of thumb.”
Data sources: CPB’s ISIS database, RRC, Arbitron, PBS Research, Nielsen.
See 170 Million Americans for Public Broadcasting: The Numbers.