I would like to understand different options of what tools are available for reporting user adoption metrics in SharePoint online that support features like # of unique users, # of visitors, # of page views, # of visitors per each site collection, site in SharePoint by monthly, weekly, quarterly, yearly, % of of users from each country etc.
Appreciate if anyone can share the information of different tools/products they have used.
Hi Prashanth,
Did you ever find a solution for tracking your SP Online environment?
Although I’m a bit biased 😉 I can recommend you check out our solution, CardioLog Analytics. The solution can offer you much deeper insights than those available in SharePoint or Google analytics. It’s available as an On-Prem or SaaS deployment.  The solution is specifically built for SharePoint, so it’s tailored to provide analytics specifically on SharePoint’s architecture. It can track everything you mentioned above.
For further information, check out http://www.intlock.com
Hope this helps!
Auditing, reporting and storage improvements for SharePoint Online and OneDrive for Business:
https://blogs.office.com/2016/02/17/auditing-reporting-and-storage-improvements-for-sharepoint-online-and-onedrive-for-business/
SharePoint Online(O365 + SP2013) web analytics:
http://sharepoint-community.net/forum/topics/sharepoint-online-o365-sp2013-web-analytics
