This being, geofilters. Now anyone, whoever you are, can make their own personalized geofilter for a limited amount of days over a limited area. This is their YouTube advertising campaign:
For example, an event covering Victoria Square in Adelaide over a weekend, would only cost US$500 which in my opinion, is a pretty good investment for the amount over Snapchat coverage you would receive. Especially if the event was aimed at young adults- the main users of Snapchat.
And it is surprisingly easy to create! All you need to do is create your graphic, select the area and time you want the geofilter to be available and viola. Instant (almost) and very cheap marketing!