At least at one point, Nielsen were getting their stats by paying people to install their iOS monitoring app using an enterprise developer certificate: http://w

At least at one point, Nielsen were getting their stats by paying people to install their iOS monitoring app using an enterprise developer certificate: http://www.arbitron.com/research/installhelp/install_ios9_en.pdf http://www.arbitron.com/research/installhelp/install_ios9_en... Including minors as young as 13 with parental consent: http://www.arbitron.com/research/faq/iBoard_faq_en.pdf http://www.arbitron.com/research/faq/iBoard_faq_en.pdf