To properly deploy the asynchronous Google Analytics tracking code (Async):
- Place the Async code at the bottom of the <head> section on all pages of your site for optimal tracking results. Missing page tags is a common issue.
- Data should appear in your Google Analytics account within 5-24 hours of deploying Async.
- For accurate reports, Async should be deployed on at least 98% of pages. Having it on less than 98% requires more data scrutiny, and less than 90% makes reports invalid.