Many people ask “How long do I have to drive on SVO to get a return on my investment (ROI)?”. This is a good question since nobody wants diminishing returns.
This posting has a good overview on ROI for a SVO system and also dives into the hidden costs of SVO. http://www.websitetoolbox.com/tool/post/voconversionbasics/vpost?id=2461566
For those who want an automated system, check out my spreadsheet on SVO ROI Calculator spreadsheet (MS Excel format).
http://thesmartdrive.com/files/SVO_calculator.xls