Interactive marketers rely on their agencies for a variety of crucial services yet often fail to evaluate their agency performance after the contract has been signed. By not formally evaluating their agencies more regularly, interactive marketers risk the opportunity to improve their agency relationships and ultimately improve their results. Agency evaluations should be completed across three dimensions: agency execution, agency service, and client direction. But it shouldn't end there: Once the evaluation is complete, interactive marketers should commit to making changes to ensure long-term success.