If you add Open Graph Protocol metadata to your website that is different for every URL (so the url in
<meta property="og:url" content="http://yourwebsite.com/somepage.html">
is the url of the page itself), you end up with an unmanageable number of "virtual" fan pages. I don't see a way to post updates to (newsfeeds of ) the fans of those individual pages all at once... Do you know of any "sitewide" update possibility?
The alternative is that you set the URL parameter in the og metadata to a constant url - either your homepage or a "traditional" Facebook Fan page. This has the disadvantage however that if people like an individual posting on your site, in their newsfeed it shows up as a like of your homepage or Facebook fan page, and the link their friends see is their homepage or their individual fan page - a behaviour that seems illogical to most people and can be perceived as spammy.
Anyone found a good solution for this conundrum?
PS: I tried to add the tags facebook-pages open-graph-protocol to this question, but lack the required reputation of 300 - maybe someone else can?