When you setup a page for tracking you enter an expiration date and visit limit. Once either of these limits is reached, the snapshot will stop collecting data, and the status will change from "running" to "stopped".

If you want to resume tracking data for your page, you can click on "edit this snapshot" and increase the expiration limit, this will reactivate the snapshot and data will continue to accumulate on that snapshot. Or you can click on "test a new version" and we will start collecting data on a brand new snapshot for that page.