Apple shares in the mobile advertising market are expected to edge up at 21% by the end of the year, according to a Jumptap report, provided via Businessweek. Google and Microsoft, on the other hand, are seeing a decline, with analysts marking a  drop from 27% to 21% and from 10% to 7% respectively.  The figures show that Microsoft and Google are losing share to Apple iAd, with number of brands running through iAd double since last June.

With the prediction of mobile advertising market value to double this year amounting to $500 million, system upgrading and acquisitions have been very popular among companies. “Apple’s acquisition of Quattro and Steve Jobs’s launch of iAd put a spotlight on mobile advertising,” says Jumptap CMO Paran Johar.

Unilever, Best Buy and Direct TV are some of the big marketers who run through iAd giving Apple an accumulated revenue of $60 million from mobile advertising. Moreover, Unilever, who first ran through iAd last July is getting more 20% of the people checking their ads again.

Though iAd is doing better in the market, it is still not growing as fast as CEO Jobs expected, when he announced it will take over half of the mobile advertising market on the second half of the year.  Early participants have indicated too much stringency associated with the iAd’s options, making it difficult to control all aspects of their mobile campaigns.  iAd is a major focus for Apple, as it builds out a monetization structure from its mobile devices and supported apps.

The Jumptap report shows a different aspect on the mobile platform wars, which has extended deeply into the advertising sector.  A number of factors, from Google’s open source approach to higher click-through rates for certain ads on one platform or another, are being considered for the growing number of ways in which mobile advertising is being measured.  Microsoft is looking to compete as well, with a recently launched SDK for mobile ads.