Tumblr committed Type Crime
Tumblr homepage is simply beautiful, minimal and to the point but they committed a type crime even in this little amount of text. Tumblr is using prime mark (a.k.a. dumb quote) instead of closed quotation mark (or apostrophe).
The purpose of prime marks, or hatch marks, is to indicate inches and feet. Their use to mark quotation is a common blight across the typographic landscape.
Details Matter :)