I don't know about today, but 15 years ago when my company held presentations about the value of print advertising that's grossly under bought, (with permission) we'd put everyone's favourite take out Pret sandwich in front of their seats, with the advertising sources on green fanfold line as placemats. We couldn't get better than 50 50 for exact choices but given the advantage of permission to obtain personal information we asked the secretaries with a (disclosed as payment for data) bribe. The line prints did the talking just as raw data - in 05 data mining was too precious for stunts and Xeon hadn't surpassed our ES45 alpha servers for system bandwidth.