Mobile ad firm AdMob launched Download Tracking for iPhone Apps, a means for marketers to monitor App Store conversion rates.

Apple's App Store enables third-party developers to build, then sell, games and mobile services to iPhone and iPod touch users. By early December, the store surpassed three hundred million downloads. It went live in July.

AdMob's Download Tracking tracks the download progress of multiple iPhone-specific applications. It also reports conversion rates by ad and date. Such data can be used to "write better ads, calculate […] return on ad spend, tune […] App Info pages, and develop better pricing strategies," according to AdMob.

Statistics already gleaned from the Download Tracking program include the following:

• Free applications are downloaded from the App Store at an average rate of 10% — 10 times higher than the 1% conversion rate enjoyed by most paid applications.
• Games have a higher conversion rate than other app categories — a 100% improvement over non-game apps at comparable price points.
• The average acquisition cost for free apps is under $1.00, far less than average (unspecified) application download costs on the desktop-based web.

Mobile marketing firm Greystripe recently launched Flash-based ad units for iPhone applications, specifically suited to games. And offerings comparable to AdMob's Download Tracking program include Omniture's App Measurement for iPhone, which tracks ad clicks, purchases and pageviews in real-time.

In July 2008 AdMob offered $1 million worth of advertising to app developers, a promotional gimmick for its "Brand and Performance" ad formats, also specific to iPhone. The company — which heavily prioritized iPhone-based ad development in 2008 — earned $15.7 million from VCs in its third funding round, which took place in October.