Sometimes Google Analytics won’t match 100% with the results in VBOUT.

There could be two main reasons behind this discrepancy:

1- Google uses different tracking technology for different analytics segments, one of them used for visitor tracking is called “image pixel tracking”. VBOUT uses jquery to track web visits. Some browsers have configurations with image tracking disabled.  Below is a snapshot example:

Some browsers block this method as part of the default settings as below:
 
2- Another reason might be the placement of the script within the body of the page. For example, your VBOUT tracking code could be placed in the header while your Google code in the footer. If for some reason, certain visitors are leaving pages before they fully load the content of the page, the VBOUT tracker could load and track the visits while Google code was unable to fully load.