Online ad spending keeps ramping up thanks to an upswing in display advertising. A new forecast from eMarketer puts online ad spending at $31.3 billion this year, up 20 percent. That is double the 10.5 percent growth rate it put out last December for 2011. The new forecast shows online ad spending reaching nearly $50 billion in 2015. What is driving this growth is display advertising. Brand-friendly ad formats such as banner ads, sponsorships, and video ads are all growing even faster than search. This year, video ad spending is estimated to grow 52 percent, sponsorships are growing 26 percent, and banner ad dollars will increase an estimated 22 percent, while search will grow 20 percent. When you add it all together, eMarketer predicts that display ad spending will surpass search by 2015.