US Mobile ad spending up by 79 percent to $743 million

US mobile ad spending is to surpass $1 billion next year, but it looks like spending is slowing down.

According to a new report from eMarketer, US mobile advertising spending will hit $1 billion in 2011, up from an expected $743 million in 2010, which itself is up by 79% from $416 million in 2009.

While mobile spending will continue to increase the rate is expected to fall and that growth is expected to come from Google’s AdMob mobile ad network, with a little help from Apple.

“IAd has served as a tremendous catalyst in the industry,” said eMarketer mobile analyst Noah Elkin of Apple’s rich-media mobile ad unit but “Over time the combo of Google and AdMob has the potential to be equally, if not more, significant [than Apple] because of the scale Google brings the medium.”

Last week, Google made an announcement that it’s on track to bring in $1 billion in global mobile ad revenue, however it didn’t break down the reporting by country, so it’s not clear how much of the $743 million it currently accounts for.

SMS messaging is still the largest ad format in mobile, projected to hit $327 million this year. However, AdMob and iAd, are expected to surpass text messaging as the primary mobile-ad medium. Additionally mobile search and display ads are expected to pass messaging in 2012.

Within mobile spending, video is the fastest growing ad medium, and that’s expected to continue through to 2014.

“Apple helped show the way with iAd. Obviously they weren’t the first, but they are really good at getting the market excited,” said Elkin. “All of that helps advertisers realize they can do a lot more branding on this medium. That’s why you’re going to see more dollars flowing into richer ad units over the next four to five years.”

[ad name=”Google Text half banner advert “]