Several top interactive marketing agencies offer proprietary technology solutions that supplement their design and marketing services. These client-facing and behind-the-scenes tools fill gaps in a swiftly changing marketplace and provide some distinct advantages over applications from traditional software vendors. However, there are significant risks in purchasing proprietary technology from a service-based company whose core competency isn't building software products. Prospective clients should weigh these risks against the benefits of using specific agency software solutions and consider how to protect themselves if they do take the plunge.