Your country: US
Reward types: Sweepstakes for cash only
Number of invites: regularly due to sofware use plus occasional surveys
Age to join: from 18 years
Prize draws: Monthly $ 10,000 cash for 10 winners, stay active on the panel
Comments: This is a Nielsen special panel (world's major market research institute). You need to install software, which permanently tracks what Web-sites you visit - online surveys may be conducted on internet usage accordingly.