Home - Grow Offline Sales Certification - Data from store visits is validated through a panel of volunteer Google Opinion Rewards participants. How many volunteer participants are there?Data from store visits is validated through a panel of volunteer Google Opinion Rewards participants. How many volunteer participants are there?2shares Facebook Twitter Pinterest LinkedIn Skype Facebook MessengerQuestion: Data from store visits is validated through a panel of volunteer Google Opinion Rewards participants. How many volunteer participants are there?1 million500,000100,0005 millionThe right answer was: 5 million