I signed up with Trotta Associates a while back and have been invited to several focus groups with them for varying product input. These guys have always been great to deal with. Today i showed up for a focus group I was invited to and since they had extra people(they sometimes over book to compensate for no shows) they did not need me but still paid me for showing up and being on time. They are always friendly and have snacks and sometimes sandwiches out for you so I think they are great to deal with.