An analysis shows that mobile now represents 20% of ad spending on the social network.
The study by Kenshoo reveals that while desktop ad sales are still dominant for Facebook, advertisers are gradually moving over to mobile.
The social data analysed more than 2 million ad clicks and conversion over the November and December 2012 period.
When Apple iOS and Google's Android tablets were compared, iOS had a 97% share of advertising spending on Facebook.
However, Android dominated on smartphones representing a 71% share.
"The world's top brands have embraced Facebook mobile advertising and we expect the channel to become increasingly competitive as new devices deliver enhanced interactive experiences," said Aaron Goldman, Kenshoo CMO.
"Marketers can cater to the specific mindsets of people using Facebook on desktop computers, tablets and phones by creating targeted campaigns," he added."
A report by eMarketer predicts that Facebook will beat Twitter in mobile ads this year.
While Twitter outperformed Facebook in 2012, Facebook is estimated to take a large percentage of US mobile ads with $387m in revenues.
Facebook mobile ad revenues are then predicted to jump to $629.4m with Twitter only generating $444m.
Emarketer predicts the U.S mobile ad market to reach $12bn by 2016