Competitions can be a great way to promote Construct 2.
I'm surprised that there isn't an official or commissioned Scirra game already out to help promote Construct 2.
I remember Blender had that god awful Elephant Dreams video (Which looked amazing). YoYo Games have released quite a few game. I'm sure there's more to add to that list.
Pull a few talented volunteers together and either produce a nice little advertising piece, tidy seller, or maybe even both!
I feel like taking part in a competition. The last one I remember was for Windows 8, which is a shame because I don't have Windows 8. Would be nice if it was slightly more open somehow. Make a PC game using Node? Get onto Steam? Make an Android game?