It remains a pretty good question. I don't know much about marketing, but is the title sponsor putting up the prize money and event costs? Prize money is about $5M right? So for that they are getting a load of airtime both on Golf Channel Thursday, Friday...major network on Sat/Sun...and mentions all of those days on ESPN, especially if something noteworthy happens. Not to mention all of the lead-up coverage and post event coverage. And the corporation uses it as a marketing vehicle internally for there top existing customers and potential ones. Works out even better if your CEO can birdie 16 at the Pro-Am (Waste Management Open) :) Plus they have a soapbox to plug their corporate message in an interview format which doesn't usually happen unless you've been indited.
I am really just guessing, am I in the ball park?