Disney, Abercrombie & Fitch, and Advance Auto Parts know what's hot; all have tapped Youngstown's SenSource to count "people traffic" through thermal imaging technology. SenSource was founded in 2002 and since then has developed a variety of high-tech counters that track people, retail traffic and pedestrians through body heat. Companies use these counters for a variety of reasons like monitoring staffing needs, measuring the effectiveness of marketing campaigns and identifying effective sales people. SenSource also offers vehicle counters and environmental counters that monitor temperature and humidity. SenSource has grown from two employees at its founding to 12 at the beginning of 2010, including two hired in 2009 in product support and marketing. The company plans to hire two more sometime this year.