The mail piece directs prospects to your website (even if you are not meaning to!). Website visitors receive a cookie via Google so that your ads follow them as they browse other sites. Website visitors who are retargeted with display ads are 70% more likely to convert on your website.
Google Display Network: Google “rents” small spots on millions of websites around the internet. These spots are used by Googles’ customers to display their ads. This is where we show your online “Follow Up Ads”!