WPP plc = holding company
Kantar Group = one of WPP's companies
Kantar TNS = a market research company, part of the Kantar Group
MarketApproach = a different company that handles Kantar TNS's mystery shops; not part of Kantar
Actually, Busy Bee is the most accurate in this thread. WPP is the holding company of Kantar. WPP purchased TNS many, many years ago. There have been lots of changes within the different companies under the WPP umbrella. Kantar is now the group that handles the mystery shopping part of the business. MarketApproach is a company I started 17 1/2 years ago. MarketApproach has managed a lot of the mystery shopping work for first TNS and now Kantar over the last 17+ years. Additionally, MarketApproach has its own clients. Because MarketApproach has grown a lot the last couple of years, we made the decision to run on two different sites. The shops we have on the Kantar site are being managed on behalf of Kantar. The shops we have on the MarketApproach site are 100% our own clients. MarketApproach handles the scheduling, editing and shopper payment on both sites. We are now paying all shoppers VIA ACH using a partner, Bill.Com to process the payments. Hopefully this helps clear up some things. We focus a lot on the travel industry and specialize in resort shops. If you have any questions, please feel free to post here and I'll make sure to follow the topic.
If you haven't already registered with us, I've including both sites here.