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Charlie is a student in EECS at MIT. He is walking down the hall when a poster catches his eye. It's an advertisement for a talk given by a UI Researcher named Bob next week. Charlie is intrigued, and he ; he is interested in Bob's work. Charlie whips out his Android to add the event to his calendar. Charlie notices the QR code on the poster has the label "Add this event to your calendar." Charlie was going to enter all the details manually, but he thinks the QR code might be faster. Charlie launches his Barcode Scanner app and takes a picture of the QR code. Charlie is then brought to a mobile page on RScanVP.com. He clicks a button to add the event to his calendar. The link opens up his phone's Calendar App app and adds the event to his calendar.
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A day before the event, Alice needs to place an order for food. She goes back in her email and finds the link from RScanVP.com. She opens the link and sees that 50 people have added the event to her calendar. She knows that not everyone used RScanVP and that some people who added the event to their calendars might not attend, so Alice decides to order food for 75 people. Alice is happy because she previously had no clue how popular the event would be.