LinkedIn plans to introduce advertising on their mobile apps, according to comments executives made during their recent earnings call for Q4. (via TechCrunch). The news follows rampant rumors that Facebook is readying its own mobile offering.

Few details were offered other than the infrastructure is in place and the company is now positioned to introduce advertising in its mobile solutions.

Growth Area for LinkedIn

LinkedIn, like most other networking sites, is seeing strong growth in its mobile channel. It accounts for 15% of all visits to LinkedIn, the company reported, which is up from 9% of traffic halfway through 2011 (via GigaOm).

Such growth is not surprising given mobile’s overall popularity. During the three-month average ending December 2011, 47.6% of US mobile subscribers used downloaded applications on their mobile device, up 12% from the three-month average ending September 2011, according to comScore Mobile Metrix data.

For the period, downloaded applications remained on par with browsers, which were used by 47.5% of subscribers (up 10.7% from 42.1%).