Mobile advertising is a big -- and growing -- market. Nearly 80 million Americans now own a smartphone and mobile ad revenues are expected to climb to nearly $3 billion annually by 2015, according to TechCrunch. This infographic from Inneractive breaks down the battle between iOS and Android, two of the most popular platforms at the moment.

Quickly, some of the terms used: eCPM stands for effective cost per mille, measuring the amount of money a developer makes for every 1,000 impressions of an advertisement in their application; global fill rate is the percentage of impressions populated by an advertisement; and CTR is the click through rate, or the number of times people actually click on an advertisement divided by the number of impressions said advertisement received.

As you'll see below, it's hard to declare a winner right now, but it's interesting to see where the two platforms differ.

Infographics are always a bit of a hodgepodge of statistics culled from a variety of sources. Here, we sort through the clutter and pull out some of our favorite facts and figures:

• While many comparisons have been made between iOS and Android, the two platforms behave very differently when it comes to mobile advertising and user behavior. The global fill rate on Android is higher, but the overall CTR and eCPM on iOS maintain the lead.
• Many factors influence the success of a mobile advertising campaign. These include mobile platform, app category, and even the specific type of app. The location of the campaign directly affects the results as seen in the map on the infographic.
• Apple's iOS enjoys a higher eCPM than the Android platform in both the United States and the United Kingdom, but Android's eCPM exceeds that of iOS in France and Germany.
  

Check out more Infographics on the Technology Channel.