In fairness, the two-year mark is probably a good time to re-evaluate the report given how much things have changed in that time. AdMob reports this month that ad requests totaled 8.3 billion in the U.S. and that worldwide requests soared to 20.65 billion last month. Over a year, that adds up to a number that’s simply too hard to wrap your head around, and as it grows, it may be comparable to Google (NSDQ: GOOG) reporting how many PC ad requests it receives during a given month.

AdMob said it began issuing this report to help the mobile ecosystem make better business decisions. In fact, the report is one of the reasons the company became so well-known, and has received so much publicity in that short time. In its farewell post, AdMob has detailed just how far things have come in the past 24 months.

Here’s some of its findings:

—In May 2008, smartphones generated 22 percent of ad requests and in May 2010 they accounted for 46 percent of ad requests. 

—In May 2008, the iPhone and iPod touch generated 1.3 percent of worldwide requests and the first Android handset was still six months from launching. Two years later, the two platforms accounted for 42 percent of all ad requests worldwide. 

—Motorola (NYSE: MOT) feature phones were the top-three devices in AdMob’s network in May 2008, but in May 2010 the only Motorola device in the top ten was the Droid.

—The Nokia (NYSE: NOK) N70 was the number one smartphone in AdMob’s network in May 2008. It dropped to number four in May 2010, but continues to be the top smartphone.

—A year ago, the HTC Dream (G1) was the only Android device broadly available. Since then, there’s no one dominant Android device. In May 2010, the Motorola Droid had the greatest share with 21 percent of the Android users.