Social Media Marketing "creative" contest scheme

That's roughly how it goes:

A brand posts online a brief with a reward for best idea (a tiny tiny fraction of what a professional ad agency would ask) and invites everybody to participate. Soon it receive hundreds of submissions from the general public participants attracted by the reward. Next step: they rate each others ideas (usually the most conventional ideas are most popular!), then the brand's jury makes its pick (usually the most popular ideas - not to upset the public!) and the winner gets his or her bounty.

Now, what happens to the rest of submissions? Here's the clever part:
They get further promotion for free by their authors as their personal creative endeavors across many other channels of social media, i.e. 'hey, check out my idea' on Tweeter, FB, Youtube, personal websites, etc. And for the brand it doesn’t really matter whether these ideas are crap or not. The most important – they keep the brand’s visibility.

So, for a price of a bicycle (or so) the brand kills 2 birds at the same time – generation of content (within the contest) and continuous promotion of the content free of charge by the same public across their personal channels afterwards. Here’s an example of a crappy idea with 936 views on Youtube.

It seems to me that when it comes to social media engagement, quality of ideas (originality, innovation, etc.) is not a priory. What really matters here is the quantity of ideas and their perpetual and free promotion on the web by the authors themselves.

Imho, I don't see this model of social marketing as a long runner.

Idea: Online public trash depository

Why not to offer a service that would allow computer users to upload deleted files from their desktop recycle bins for storing them in a global public recyclebin? Anyone is free to scavenge for salvageable material, download and reuse it.

Once the volume of submissins reaches, say, half a million uploads, the site will introduce a public contest to reward the best recycling ideas, for example re-use in digital arts, in sociological studies, etc.