Check out these 15- and 30-second public service announcements that ALA created to run on the Lifetime TV channel.
While it's the right message for the right audience, I'd love to know how that Lifetime target market (middle-aged women) was chosen. I suspect that mothers are a core group that already visits libraries often with their children. Personally, I'd love to see ads aimed at 40- to 70-year-old businessmen, since they frequent public libraries much less often but hold more of the positions of power where their votes affect funding.
Still, it's nice to have these available for use on your own websites. Use them for all they're worth!