XP

This is strictly concerning the PC version of Chrome.

Chrome has a profiles option that is a huge game changer if you need to manage multiple accounts. Extremely vital if you use either google docs (create 1 profile for each account that uses google docs) or more than 10 accounts (each profile can hold up to 10 accounts).

It's also useful for managing a lot of tabs with the reopen tabs feature. Google Chrome normally only saves one browser worth of things and opening more than 100 tabs on a single instance of Chrome is very annoying. You won't be able to access newer tabs until you've closed older ones as they will become hidden. There isn't even a way to close those newer hidden tabs (happens after ~100 tabs).

Each profile can thus be used to efficiently store an additional 100 tabs, however that's pretty much overkill.