10.10 To Share or Not to Share
Google requires the use of an API to collect user data because APIs provide better protection for that data. Beehive users have the option to use a shared API (Connect with Google) or to create a custom API project (Set up API project) specifically for their sites.
We strongly recommend creating a custom API project using the instructions provided in this guide.
It must be said that the Connect with Google method, typically, is very quick and easy to set up. However, it’s so simple because it uses an existing, hard-coded API that is shared by multiple users. Google limits the maximum number of requests a single API can make per hour and per day. A shared API significantly increases the chances of hitting this limit and distorting your stats.
Creating a custom API project, on the other hand, creates an exclusive connection just for your site or network. This custom connection ensures your stats will be as accurate as they can be, and it is extremely rare for a single user or even a single multisite network to reach the Google Analytics API limit. See Limits and Quotas on API Requests for more information on the limits of shared APIs.
However, it is important to note that Google does have a hard limit of 50 “refresh tokens” per account. That means that you can connect up to 50 domains using the same account. So if you do have lots of sites, or a multisite with lots of domain-mapped subsites, you might indeed hit that limit, and random sites will start displaying “unknown error occurred” messages. See Refresh token expiration for more information on that limit.
Workarounds for the above situation could be to have only 45-50 sites on one account and create a different account for additional sites. Or add an additional user to your account to be able to add more sites to that account as that additional user.