158439Like a number of people in the music industry, we’re keeping a keen eye on the mobile advertising market, and wondering what its potential is for digital music services.

eMarketer’s new research breaking down global mobile-ad dollars between Google, Facebook, Pandora, Twitter and other companies is thus a thought-provoking read. The topline figure: eMarketer expects global mobile ad revenues to grow 79.7% from $8.8bn in 2012 to $15.82bn in 2013.

It expects Google to hoover up 56% of those 2013 mobile-ad dollars: $8.85bn. It’s then a long way down to Facebook’s 12.9% market share with $2.04bn of mobile ads this year, and another drop to Pandora.

eMarketer expects the personal radio service’s mobile ad revenues to rise from $240m in 2012 to $400m in 2013, giving it a 2.5% share of the global mobile advertising market.

Yellow Pages ($380m) and Twitter ($310m) round out the top five. Between them, Google and Facebook will account for 69% of all mobile ad spending this year, if eMarketer’s predictions are right.

The research makes us wonder again why Google doesn’t currently seem to be interested in adopting an ad-supported approach for its Google Play Music All Access streaming service, which for now is a subscription-only affair.

That said, Google’s mobile ads business may have a growing role to play in helping other digital music services attract ad dollars on mobile platforms. Pandora aside, to this point it’s been Indian streaming services like Dhingana and Saavn that have been more active in this area.