I've had the honor of working with the Ad Council multiple times in my career.
Some of the most satisfying work as their projects usually have very little to no money and are always centered around a cause -- which is a nice change of pace, rather than just capitalistic efforts.
Specifically the GED Call Center was a project that really pushed my sanity. The Brief: Multiple celebrities to endorse getting a high school diploma through the GED program -- told online, through broadcast and via the 'call center'. Each celebrity would give a different tonal pep talk from gentle to aggressive. Were celebrities being provided? No. How much money? $0. When would they like to shoot? Over the holidays.
Good luck.