I'm helping to troubleshoot this problem, and hoped the collective expertise here might help find the culprit.
It seems that a site, using the Multisite Analytics plugin, has a problem where all visits are treated as a new visit. Also, it doesn't track the path of any visitor across content – each time they hit a new page/post it is treated like a brand new visit even if they were already on the site.
This is happening on all blogs in the multisite network.
See screenshot. Seems weird and I can't find anything similar on Google…