Market Research Firms or Recruiting Specialists - I

Market research firms recruit people for their client's marketing studies. A few firms specialize in recruiting participants for usability studies as well. Consequently, they will know exactly what you are talking about when you tell them that you need particular end users for a research study. Some market research firms may not understand usability testing per se, but bringing in computer users, scientists, doctors, lawyers, chemists, general consumers, and so on, for the purpose of gathering opinions and preferences is their business.
The larger ones can get any type of person you ask for, for a price.
Almost all major cities now have at least one market research firm. Because they network with each other in order to conduct studies around the country and internationally, once you find a good one, you can usually find another agency in a different city if you need to. With so much communication being done electronically, a recruiting specialist based in one city can easily recruit participants in other places. These firms therefore are the vehicle to use when it is important that you conduct usability testing in different geographical
locations. They can also help with some of the other types of research tasks, such as surveys and focus groups.