Take on the Free Wifi in a drive through

Can somebody explain to me why a Starbucks drive-through on a major
artery would advertise free WiFi on their drive through window? In
the 3 minutes it takes to order a large coffee and then explain that
is a Venti or Grande, Biggie or whatever, you have no time to find the
WiFi signal, log on, register etc to make it worth exposing all your
valuable secret information to Chechnyan hackers