No long-winded introduction this time. Here’s the comparable post for public library blogs. I used the same sample period and rules for *Academic Library Blogs: 231 Examples*: March-May 2007, blogs had to have started before 2007, blogs had to have at least one post in two of the three months.

In all, the 232 blogs included 6,229 posts, for an average (mean) of 27 posts per blog–about two per week. The median is 14 posts, just over one per week.

The quintiles:

- Q1: Most frequent posts: 34 to 762 posts.

Average (mean): 83.4 posts.

Median: 52.5 posts.

This quintile includes 61.6% of all posts. - Q2: More frequent posts: 17 to 34 posts.

Average: 24 posts.

Median: 23 posts.

This quintile includes 17.8% of all posts. - Q3: Average posting frequency: 11 to 17 posts. (The “extra” blog is here.)

Average: 14.5 posts.

Median: 14 posts.

This quintile includes 11% of all posts - Q4: Fewer posts: 7 to 11 posts.

Average: 8.9 posts.

Median: 9 posts.

This quintile includes 6.6% of all posts. - Q5: Fewest posts: 2 to 7 posts.

Average: 4.2 posts.

Median: 4 posts.

This quintile includes 3.1% of all posts.

What percentage of blogs do I need to include for 80% of all posts (the Pareto number)? Quite a few–95 in all, or nearly 41%. That’s not surprising: After four blogs with 762, 468, 240 and 114 posts respectively, none of the blogs averages one post a day, and the number of posts declines fairly slowly.