Most people would expect an executive position on Google's ad team to be the pinnacle of their career. Well, until Facebook started to prove itself as a real competitor to the once-undisputed online leader. 37-year-old David Fischer used to be the Vice President of Global Online Sales & Operations at Google. Now, he's heading up Facebook's advertising department. "It's a testament to Facebook's expanding opportunities in advertising that we're able to welcome an executive of David's caliber," said Facebook COO Sheryl Sandberg in a statement. Since its inception in 2006, Facebook has proven its worth as the leader in social networking and innovation. But certainly no one would have expected that in just a few years it could actually be a legitimate challenger for the hottest online property. Some statistics even prove Facebook as a better online site. For example, users directed to news outlets on Facebook become more loyal to those sites than people directed there from Google. Earlier this month, it mind-bogglingly surpassed Google in the US as the most-visited Web site. Though it took a while to catch on, advertising on social media sites has proven to be valuable because they can be more easily tailored to individual users. To say the least, when an online company can attract key people from Google, it's doing something right.