When clients are selecting a new agency, a strong knowledge of the industry trumps all other factors, according to a new study.

Clients said that "having an understanding of their marketplace" was the most important issue when selecting a new agency, according to a survey by consultancy firm Reardon Smith Whittaker. Grasping the brand's strategic direction and examples of creative work were tied as the second-most-important factor, followed by "offering something fresh and new."

"Given the challenges clients are facing in light of the economy, they need agencies that can get up to speed quickly, add smart value-added thinking and are a trustworthy lot," Mark Sneider, managing director at Reardon Smith Whittaker, told AdWeek.

The study, which polled 184 client marketing and brand executives, found that the No. 1 reason clients look for a new agency is because they are unhappy with their current agency's thinking. Unsatisfactory creative and the agency not being proactive enough were the next most popular reasons why agencies look for a change.