Alexa top 10,000 and rel publisher, opengraph tags, and schema

Alexa.com might not be high in their own rankings, but they provide a very, very handy list frequently - the top 1 million domains by estimated traffic rank.

The accuracy of this data is beyond my knowledge - only Alexa has detailed insight - but I would think that this list is at least directionally right and rare in the way it is offered (Quantcast offers something similar). Thanks Alexa!

I wondered how widely used tags are, we (at SEO for Dell) consider important or at least interesting.
I wrote two small scripts to test for the implementation and also to calculate or count, and here are the results.

Tested for 3 elements:

1. og:title - checking for the implementation of anything related to opengraph.org tags
2. rel_publisher - if the tag is implemented on the homepage, as recommended by Google
3. schema - this tests for implementation anything related to schema.org, according to the search engine recommendations.

All items are only tested on the homepage of the 10,000 domains! And if a domain did not answer - some are not set up properly and do not forward to a default subdomain like www - all values are set to 'no' by default. I manually checked the first 400 urls, and this happened twice.

First observation - these tags are FAR from everywhere. 

Opengraph is on ~ 26% of homepages, rel publisher on 17% and schema only on 10%.
(First column = line counts)

Second observation is interesting, but seems a relatively weak correlation:

The implementation of opengraph,  rel publisher and schema happens slightly more often on the higher ranking homepages. This is most pronounced for schema, least for opengraph, which has the highest overall adoption rate.

Is this compelling you to implement on your site?