OK, I'm going to go off-topic and sound like a crank...but is the font-size for Google's blogs kept at 13px because:
1) To keep consistency across every service (search, analytics, maps, etc)
2) Because it's what users like, according to in-house studies
3) Because...why change it?
Not all the Google blogs use Arial (http://chrome.blogspot.com/ uses Open Sans). I'm not trying to be completely snarky here...If it is indeed a best practice, then that's good to know. The width of the Google blogs do conform to showing 80-or-so characters a line, though at 16px, the characters-per-line is about 70, which isn't bad either.
(yes, I know HN is at 13px too...but a discussion board with variable length of text and a higher value in being able to see more entries at once is different than the narrative paragraph form)
So that I'm still able to read it on my 640x480 CRT screen. Backwards compatibility is serious business at Google.
Joking aside, it's a 62.5% x 1.2em font size which is rendered as 12px (at least with my chromium/ff defaults). Probably too small for most readers nowadays (some would certainly agree cf. http://informationarchitects.net/blog/the-web-is-all-about-t...).
1) To keep consistency across every service (search, analytics, maps, etc)
2) Because it's what users like, according to in-house studies
3) Because...why change it?
Not all the Google blogs use Arial (http://chrome.blogspot.com/ uses Open Sans). I'm not trying to be completely snarky here...If it is indeed a best practice, then that's good to know. The width of the Google blogs do conform to showing 80-or-so characters a line, though at 16px, the characters-per-line is about 70, which isn't bad either.
(yes, I know HN is at 13px too...but a discussion board with variable length of text and a higher value in being able to see more entries at once is different than the narrative paragraph form)