What do Facebook, Foursquare, and Twitter all have in common? American Express (NYSE: AXP) is using each network to broker social transactions, and in the process is proving there are tangible reasons for everyday businesses to get involved in the social sphere.

While each arrangement is different, the essential elements are the same. Link an American Express card to your social network and get access to deals. Here's a closer look at the various options:

Where is LinkedIn (NYSE: LNKD) in all this? Nowhere yet, and I don't expect that to change soon. Retail commerce isn't in LinkedIn's DNA. Nor is social media. Rather, the company is a big data play that's beautifully positioned for how it aggregates and presents career information that wasn't easily accessible before.

American Express goes further by arranging transactions that might not occur otherwise. Everyone wins, giving the soft, murky opportunity of "social media" a hard currency edge. I like the idea enough that I've made an outperform CAPScall on American Express in my Motley Fool CAPS portfolio.

Think I'm wrong? That American Express is the exception and social media is an overhyped, sure-to-disappoint fraud? So be it. Safer choices are out there, including these six stocks that top professional investors are buying now.

Fool contributor Tim Beyers is a member of the Motley Fool Rule Breakers stock-picking team. He didn't own shares in any of the companies mentioned in this article at the time of publication. Check out Tim's web home, portfolio holdings, and Foolish writings, or connect with him on Google+ or Twitter, where he goes by @milehighfool. You can also get his insights delivered directly to your RSS reader.

The Motley Fool owns shares of Whole Foods Market, Best Buy, and LinkedIn. Motley Fool newsletter services have recommended buying shares of Whole Foods Market and LinkedIn. Motley Fool newsletter services have recommended creating a write covered strangle position in American Express. The Motley Fool has a disclosure policy. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. Try any of our Foolish newsletter services free for 30 days.