42% of URLs have Open Graph tags

"Embedly's crawler doesn't go out looking for URLs. We only process URLs that have been shared through our API. You can then postulate that our Open Graph average is actually higher as the sites that are shared more are optimized to be shared in Facebook."

FB is amassing a huge database of well organized & socially relevant online documents that other companies are going to have a hard time even coming close to. It's like PageRank on steroids.

- It is verbose and bloats the page. You have a dozen of tags in the best case, but if you have an album of something you might need to provide a set of og tags for every object, which is a lot.

- You often need a different set of og tags on the same page in order to make facebook treat that page differently (you can be doing different things on the same page). So you end up serving a special version of page with og tags to facebook by user-agent.

For simplier cases, you don't even need og, and for more complicated ones, they are facebook-specific and you'll have trouble using those for anything else.

The overall experience from og and facebook: Bad. Don't like.