People may react faster to email advertisements, but they are more emotionally attached to hard copy mail, according to a USPS Inspector General (IG) June white paper. Direct mail made up 31% of USPS total revenue in 2014. The IG worked with Temple University’s Center for Neural Decision Making in a study to determine consumer’s responses to physical and digital media. The findings: physical mail is more likely to lead to consumer purchases. Understanding how people respond to physical mail could help identify new opportunities, according to the IG.