Interaction Powers Success. This philosophy comes to life every day at The Gillespie Agency. Based in Columbia, South Carolina, The Gillespie Agency is a full-service advertising, media and public relations firm which has been named the Midlands of South Carolina's second largest according to The State newspaper. The agency provides comprehensive marketing services for a diverse group of clients. Straight-forward thinking is one of the qualities of which The Gillespie Agency is most proud. Combine that with our portfolio of award-winning work, and it's easy to see why clients remain committed to our agency. Every ad agency can produce great print and exciting electronic advertsing, but we believe there is more to marketing than cool creative. Our clients' profits are more important. Ultimately, what everyone wants is results. And results are exactly what The Gillespie Agency provides.