Hey Scott,
There are most likely many ways to do this and it depends on how your lead database is set up and the other values on the lead.
If you imported this theorhetical lead and added them as a member to a Road Show a year ago, you could create a Smart Campaign like the following:
![0EM50000000SVda.jpg 0EM50000000SVda.jpg](/t5/image/serverpage/image-id/1096i3100CC33E7677086/image-size/large?v=v2&px=999)
Here, we are acting on leads who are a member of a 2013 program and who also register for the 2014 program. In essence, leads who were added to this event a year ago and now are registering for a new event. In the flow of this campaign, you could change this lead's score or send an alert as you please.
Best,
Will