People, just like you and me, have now become the major information source when it comes to marketing, advertising, recommendations and ultimately, the decision to purchase. The omnipresence of social media, means that EVERYONE, is now potentially your advertiser, because EVERYONE, now has a voice. In essence, what was once siloed as offline word of mouth has now become potentially viral, word of mouse.
Given the context of the ALS IBC, some may see GoPro using this cultural phenomenon for commercial gain as a tad evil and in bad taste. However, as a piece of social marketing, this content leverages the power of word of mouse and has sent the GoPro brand message to thousands of people organically - with as few barriers to consumption as possible - and I personally think they did an awesome job.