A simple idea, based on a popular platform using the most common user behaviour usually creates great results. I've always been a big fan of 'tagging' and have constantly tried to apply the behaviour to brands that I work with. That said, you've got to fit the behaviour with the product or brand and you can't force-fit a strategy just because you like it (believe me, I've tried).
But for IKEA, this is the perfect fit with a great, creative, promotional idea. So simple.
I'd be interested in understanding the media support they had behind this campaign and whether it truly was all viral (which I doubt). That said, the 'first tag, first win' approach creates a rapid fanbase who is always waiting for your next photo upload.
Excellent work. Found via Mashable.