"One would be there’s a BIA/Kelsey report out that says that the localized spending globally is about $150 billion at a local level. The other way you could look at it is of that, there’s about—again, I think the same report or something similar says that Yellow Pages globally is about a $24 billion market, of which there’s about $9 billion or $10 billion being spent in the U.S. alone."
Source: Seeking Alpha
Source: Seeking Alpha