For all of us who’ve been using Gmail as a primary email account, you’re probably interested to find out how you’ve been interacting with Gmail. Google may be working on this already, we’ll never know, but in the meantime, developer programs engineer on the Gmail team has written a Gmail script which he called Gmail Meter. The script provides you with a report at the start of every month about how you interact with Gmail. It also lets you generate reports about your Gmail activities. Gmail Meter also shows you statistics on the volume of email sent and received with breakdowns of how many messages you have starred or marked important, daily traffic estimates that show your heaviest email days, email categories that tells you how you manage your messages via Gmail labels, time before first response or how long it took you to reply to an email for the first time, average length of your email messages, as well as who are you top senders and recipients. Since the script is not an official Gmail add-on, you need to it up by opening a spreadsheet on Google Docs. Then click on Tools > Script Gallery then search for Gmail Meter and click Install. Once this is done, you’ll see a new menu item labeled Gmail Meter on your spreadsheet. To generate the report, click on Gmail Meter > Get a report.
Via [Gmail Blog]