I'm sure there are many benefits for MySQL being a part of a large IT vendor like Sun Microsystems, but the advertising budget probably doesn't hurt. Reading Businessweek today at lunch, I bumped into this MySQL advertisement in a super-prime location (right next to Wildstrom's Tech and You column).
I would hazard a guess that MySQL spent close to $0.00 on advertising when it was a standalone company. I doubt Marten, Zack, and crew are complaining. :-)
It will be interesting to see if this top-down approach will help to drive more MySQL sales. Open source has always been a bottom-up phenomenon, but perhaps once a project reaches a certain stature marketing and other "grown-up" software activities can go a long way?
At any rate, it's clear that open source has come a long way when we start advertising in major business publications like Businessweek.