[huhtenberg]

> Bounce Rate

This requires tracking sessions.

> Page Views per Session

This requires cookies or some other mechanism for stringing individual page hits into a single stream. While you can, sort of, kind of, do that based on the source IP combined with the user-agent (like this project does), it's not terribly accurate and it can't track longer sessions.

I would argue that very few people object to being tracked by the site they are actually visiting. Most object to being tracked by 3rd parties, and across multiple unrelated sites. So a simple 1st party cookie is quite acceptable, but you can certainly go an extra mile and ask even if it can be set.