Each site records its own visitor figures, so you can see how it is doing without adding anything to the site itself.
Where
Open a site and select Monitoring.
You get unique visitors over time, how long people stay, how much bandwidth the site is using, and which countries visitors came from. The period is adjustable.
A shorter summary is on the site's own page under Site Details, if you only want the headline.
What it is, and is not
These figures are counted by the server, so they include some traffic that is not a person — search engines and other automated visitors. That makes them good for spotting trends and sudden changes, and less suited to precise marketing reporting.
A sudden jump in bandwidth with no matching jump in visitors is worth investigating — it is sometimes the first sign of trouble. Ask us if you see one.