Variance in Google Analytics vs. Lead Liaison Visitor Tracking

Q: I notice differences between Lead Liaison and Google Analytics for website visitor tracking. Why is there a difference? 

A: There are several factors to consider here including the following:

1. There JavaScript code might load before ours and perhaps count people that exit early off the first page
2. Visitors within a 24 hour period are associated with the same visit
3. Daily visits are recorded between 12:00AM Central to 11:59PM Central