Object types
In order for your object to be represented within the graph, you need to specify its type. This is done using the og:type property:
<meta property="og:type" content="product" />
The base schema includes the following types. It's possible that social networks will choose to support only a subset of these types or create additional types based on their niche.
Comment Trip advisor a relancé son application Facebook "Les villes que j'ai visitées" en utilisant l'open graph. Résultat : un trafic multiplié par 10 (avec l'aide d'un peu de pub, quand même)