Google Analytics - Collection limits and Sampling

Question

Can anyone give an overview of what happens when GA starts to enforce Sampling in the event that the Collection Limit exceeds 10million hits within a particular month.

Q1. Is this a soft limit? i.e. is 12/13 million okay, what effect would a consistent 30million have?

Q2. Is sampling applied mid way thru a month or does it just appear and start at the beginning of a month.

Q3. Does the sampling effect standard overview facts such as sessions, pageviews, bounce rates etc or are these based on unsampled data.

Q4. What information, reports etc will the sampling start to impact?

As context we currently have a site that is logging around 9million hits via pageviews per month and we are about to add events that will probably add 2 events per page i.e. we will be heading towards 30 million hits.

Thank you for you help.

Answer 1

Adding events should not change the number of sessions, as one session can have 0 or more events. While you are already close to the limit of sessions, I do not believe this is a hard limit.

From my experience, they will either automatically begin sampling on the account if you go well over, and they will also contact you about upgrading to premium. The sampling should not change any of your overall metrics (page views, sessions, etc) but when looking at reports such as demographics and many of the much more specific reports will be subject to sampling. While they will be sampled, I have found that they normally are consistent with what would be expected for the real reports and do not have too horrible of an effect on reporting.

Answer 2

For free users take a look at:

https://developers.google.com/analytics/devguides/collection/analyticsjs/limits-quotas

If your company has the money, you should consider upgrading to a premium account, is not cheap thoug ($150,000 per year as 4/2015).