All it takes is a little lateral thinking, and everyday (free) apps could be repurposed to run a large promotion without other media support.
This campaign for Turkcell mobile company is a great example of that. To raise awareness of the launch of new smartphones and mobile internet plans, they created a Twitter-based game.
First they put the prize in a box and then covered that box with plenty sticky notes, finally the box was placed in camera view and broadcasted online. For people to ‘unpack’ the box and win the prize, they had to tweet what they saw on the post-it notes along the hashtag #turkcelltweet.
Simple, comparatively inexpensive and very engaging for the audience.