Want to take a crack at where to concentrate the bulk of your mobile marketing resources for the rest of 2012? In the US silly! That’s right, according to eMarketer, spending on mobile internet advertising in the US will top all other countries in the world for the first time this year, helping drive mobile ad spending worldwide to $6.43 billion in 2012, according to eMarketer’s first-ever forecast for worldwide mobile advertising spending.

Until this year, Japan was the world’s largest market for mobile advertising, with spending reaching $1.36 billion in 2011, up from $1.01 billion in 2010. Mobile advertising is more mature in Japan, which means growth is far lower than in North American markets. eMarketer estimates spending on mobile internet ads in Japan will grow 27.2% to $1.74 billion in 2012, versus 35.4% growth in 2011.

Let’s have a peak shall we:

“Mobile is an exciting, fast-growing category, but it’s still a very small piece of the overall ad pie,” eMarketer says. “Mobile advertising accounted for less than 1% of total ad spending worldwide last year—and it will be a long time before it challenges other mainstay global advertising channels like TV, print and internet ads.”

The key elements from eMarketer’s forecast are:

• Mobile is growing more quickly than every other segment in the digital advertising.
• U.S. mobile advertising spending will reach the top for the first time this year.
• APAC’s mobile advertising market is far bigger than the European.
• Mobile advertising expects to take a record 11% share of total ad spending by 2016, in the UK.

How are your mobile marketing and advertising efforts shaping up? Are you tackling the US or going International? Let’s discuss in the comments below!