IDEO is the largest design consultancy firm in the United States, generating $120 million in revenues in 2008. It created some of the most recognizable technology icons like the first laptop and mouse. IDEO uses "Design Thinking", a human-centered methodology to design products that solve problems and offer superior experiences. Some major clients include AT&T, Ford, Nike, and Eli Lily. IDEO's success is attributed to its human-centered research methods involving observational studies to understand customer needs and viewpoints. However, conducting this type of in-depth customer research presents challenges such as subjective interviews, time and cost constraints, and small sample sizes.