The threats of social media on sponsorships today effect many businesses in both positive and negative ways.  I read this article about brands competing for advertising at the Olympics.  Companies such as Nike can blow up social networks such as twitter with Nike ads on the Olympics and plaster the Internet with them, while other companies pay for sponsorship in the Olympics and don't get as much coverage.  This makes the businesses that do sponsor lose money and not want to invest again, affecting the income of events like the Olympics.  Companies such as Nike do this.  Nike also uses the the halo effect for a lot of their advertising.  This  means that because you liked their product once, you'll buy another one just because it is the same brand, not because it is the better of the products.  It is a loyalty thing, you liked the way their shorts fit, so you bought their cleats for football.  This technique also helps them out when it comes to brand equity.  Basically, because you enjoyed their product once, you will spend more to get that product again, even if the same product from a different brand is cheaper.  In the article it talks about how they are limiting what companies can do to sponsor themselves in the Olympics, so that the companies that pay for sponsorship, are the ones who get it.  Nike uses their #makeitcount campaign to get out there by referencing the Olympics without directly talking about it.  This gives them the advertising with the Olympics but it gets around all their rules for it.  I think it is a good idea to keep out the companies who didn't pay from being sponsored.  They did not contribute so they shouldn't get to get their brand out there using the Olympics, while the ones who paid deserve all the promotions and business gained from the Olympics.  
To read this article yourself:
http://www.prdaily.com/marketing/Articles/12219.aspx