Sramana is suggesting that PDF has real value add and that the company should be an attractive acquisition candidate to a major EDA vendor. I do agree, DFY/DFM products that really work have a tangible benefit on chip companies' bottom lines. It's easier to appreciate and quantify DFM than that other great hope of EDA, "ESL".
One drawback is if the customer base is just foundries (like TSMC) and IP providers (like ARM Holdings), then the number of customers is not very large. Many fabless semiconductor companies won't need a big investement in DFM, at least not until such tools move up into the design implementation process.