Ken Fisher's Price to Sales Ratio (PSR) is now a part of core financial curriculum, which some consider a low risk way to identify out of favor stocks. Using PSR with more conventional factors such as debt/equity ratios, liquidity measures, and R&D relative to market share, generally enables investors to determine for themselves where the spectacular profit opportunities lie.

"VERY useful! Worth many times its price."
- John Train, author of The Money Masters and Preserving Capital

"I have found Price Sales Ratios are also useful for private companies and venture capital valuations."
- Jack McDonald, Professor of Finance, Graduate School of Business, Stanford University