If Facebook wants to be the king of hill, they’re going about it the wrong way. The number of useless apps that cram my Facebook feeds with useless “top friend invites” and “super hugs” is just too much. Those of us who would prefer a more serious social network tool would prefer the closed, no-frills approach of something like a LinkedIn, which doesn’t allow “apps” to be added, and tries valiantly to keep nuisances to a minimum.

Still, LinkedIn is for business-oriented users, and will never have the flexibility or wide-audience draw required to make a ubiquitous, dominant social network. People go to LinkedIn because because of its tight focus, and, in many cases, that’s why people avoid LinkedIn as well.  And in the end, tools like LinkedIn won’t suffice to help salespeople, because it’s mostly sales people than inhabit its garden (let’s face it).

Buying and selling aside, I’ve been doing a ton of thinking about social networking lately, because I was charged with creating a social network for a company in the media business. This social network is geared around a specific pastime of American culture–a vertical subject area too narrow for a Facebook to be excellent at.  What’s more, this social network wouldn’t be a good extension of a large publisher or broadcaster already involved in this pastime, because traditional media is bent on subcription fees and a lack of openness that discourages adoption.

So there’s a specific role for culture-driven social networks, things geared around video (like YouTube), sports, and music, though none of these verticals has been dominated by a single player, except for video probably. What’s needed is a social network infrastructure that allows many enrollment-based sites to be used with a common access credential–that’s right, a single sign-on for many social networks.

Google’ OpenSocial offers some of this thinking, but adoption has been laggard. Another example is Gravitars, which allow a common avatar picture across many blogs. Gravatars is supported by WordPress and Typepad, among others.

The challenge to seeing a single sign-on implemented across the medium is that the players who are big enough to make it happen (Facebook and MySpace, make no mistake) won’t do it, because they’ve gone into revenue-sucking mode.  So time will tell.