Appropriately called “Listening Screen Takeover,” the new service allows marketers to overtake the app listening screen while iPhone and iPod touch users are identifying songs.  Instead of the familiar blue Shazam screen, users running the free, ad-supported version of the app will instead see ads stretching across three quarters of the device’s  screen.  When the Tag result is displayed on the next screen, the ad becomes an expandable, interactive banner.

The company says the new ads won’t add to the time it takes to tag a song, and that’s it’s still possible to buy music via iTunes, watch video clips or share discoveries as normal.  For advertisers, campaigns and promotions can be tailored and delivered to specific advertising regions, and brands can even purchase exclusive full-day sponsorships.

While it sounds simple enough, the Shazam service itself is ripe for mobile advertising and the company is leveraging it perfectly.  Anyone who’s ever used Shazam knows that when you’re waiting for a song to be tagged, you’re starring hard into the blue screen anticipating the artist and song name information.  Add the fact that some 75 million users leverage Shazam across the world, with over a million new users a week, and it provides a pretty unique opportunity for mobile advertisers.

In leveraging its unique niche, Mobile Posse issued a press release today boasting it now reaches over 2 million opt-in mobile consumers on a monthly basis, serving nearly 200 million impressions each and every month and garnering double-digit click-through rates in the process.

“The two million unique user mark is a key milestone for our company,” said Jon Jackson, Founder and CEO of Mobile Posse. “Our rapidly growing subscriber base and the high consumer engagement we deliver underscores the value that active idle screen messaging provides to mobile consumers, advertisers and wireless carriers.”

Mobile Posse has done a good job at positioning itself as a pioneer and clear leader in interactive mobile advertising for the “active idle screen.”  The platform allows advertisers and wireless carriers to proactively engage consumers with graphical and interactive messages via the idle screen of mobile phones, while allowing consumers to opt-in to receive helpful and timely information, like weather forecasts and local gas prices, along with valuable offers from national and local advertisers.

Part of its growth is attributed to strategic partnerships with carriers, including Verizon Wireless, MetroPCS, and Leap Wireless.  With the introduction of its “MobiCRM” solution, carriers now have the ability to deliver full-screen, full-color CRM messages supporting customer service and product initiatives as well.