Note: Counts represent Gmail threads, not individual messages.
Also: These numbers do not include spam.
In order to better understand the time I spend in Gmail, I decided to count how many messages I've received so far this year (01/01/10 – 05/05/10). To do this, I searched my Gmail in various ways (see search strings below inboxes above) and clicked "Older" 1,592 times (seriously) on Gmail's search result display to get an accurate count. NOTE TO GOOGLE -- please build a better way for folks to see these numbers.
The upper right visualization is my inbox on a typical day. The messages that get filtered are mostly mailing lists. The social media-specific messages (red and yellow envelope) are museum-related Google Alerts, blog comments, follower notices, etc.