Social media is not the place to market to mainstream consumers. Social media IS a place to connect informally and loosely with distant family or acquaintances you’d rather not call or email. People are not receptive to marketing messages on Facebook, just as they’re not receptive to the farm animal their annoying “friend” needs.
Twitter is a business-to-business marketing vehicle exclusively, though good luck getting your tweet actually read by more than three people. Facebook is a loose online social club. Why do you think people will buy your smart phone, digital camera or HDTV because you put an ad on their Facebook profile page? They won’t and they don’t.
Your money and your energy is much better spent on non-social media, where people actually pay (at least some) attention: TV news, radio, talk shows, newspapers, magazines. Good mainstream media PR trumps fleeting social media mentions every time.