In Short

iAd was announced on April 8, 2010 as Apple's way to help developers make some money on free apps by showing advertisements that were both well designed and much more engaging than the typical, crappy mobile apps widely used in the industry. Apple had originally intended to jump-start iAd by buying then-independant mobile ad network AdMob, but Google swooped in and plucked AdMob out from under Apple so Apple bought Quattro Wireless instead.

iAd originally worked on a 40/60 split for Apple and developers but has since changed to a 30/70 split. iAd campaigns were also originally envisioned at the high-end, with potentially million dollar spends attached to them. That amount has dropped drastically over the years.

Apple maintains an iAd Gallery app in the U.S. to showcase iAds (last updated in 2012), iAd Producer to help registered developers create and polish their iAds, and iAd Workbench to create and manage campaigns.