South Africa, July 31 -- Often, the debates begin long before anyone leaves home. Where should we stop for lunch? Which garage has the cleanest restrooms? Which farm stall has the best pies or biscuit selection? Which guesthouse is worth an overnight stay?

Everyone has an opinion. Most of the time, those decisions aren't based on facts at all. They're shaped by memories, assumptions or something someone once heard from a friend. Sometimes those choices work out brilliantly and you feel like you've struck travellers' gold. Other times, you drive another hundred kilometres with nothing but Stop-and-Go's to keep you company.

Media planning can be surprisingly similar.

When planners build regional radio schedules, it's easy to make decisio...