Twitter advertising includes conversion tracking and re-marketing tools.
Open graph description entity tag
The Open Graph protocol enables any web page to become a rich object in a social graph, a open protocol supported by Facebook
Open graph title entity tag
A canonical link element is an HTML element that helps webmasters prevent duplicate content issues by specifying the "canonical", or "preferred".
Google's hosted library for web fonts. Allows websites to choose and use fonts from a free, wide variety of fonts.
Typekit is the easiest way to use real fonts on the web. It's a subscription-based service for linking to high-quality Open Type fonts from some of the worlds best type foundries.