The document discusses how using personalized URLs (PURLs) in direct mail can improve marketing return on investment by capturing online responses. It describes how PURLs can be used to direct recipients to a personalized landing page with a survey. Automated follow-up emails are then sent based on their online activity to continue engaging with them. This allows capturing the 33% of direct mail recipients who prefer to respond online, with response rates typically lifting by at least 2x through relevant messaging and PURLs.