Wahlstrom has developed a proprietary system for Yellow Pages market analyses: the Directory Insights System®. This system is not a pre-programmed black box, nor simply a computerized system into which variables are fed. Instead, the Directory Insights System® combines an expert analysis of the client's market with computer planning and analytic capabilities. The system integrates and statistically weighs various client-specific variables (e.g. sales, demographics, competitive advertising data) to identify and determine appropriate advertising weights for our clients by market, by directory, by heading.