Which company is the top dog of mobile? Analyics firm comScore found in a new report that music service Pandora and social network Twitter have the best mobile game in town.

By observing the total traffic, desktop traffic, and mobile traffic of dozens of websites for the month of September 2012, comScore was able to determine the most heavily visited websites for each category.

Let's start with Pandora, which had the greatest concentration of mobile users. The company's mobile audience is reportedly twice its desktop audience; 48.6 million to 22.6 million. It was the only company on the list with a mobile audience that was superior to its desktop audience. Though, the company ranked 23rd for overall traffic, with a total digital community of 56.8 million people.

"It conforms to how people experience media brands on a day-to-day basis,” said Andrew Lipsman, comScore's VP of industry analysis. "I pretty much don't use Pandora on my desktop."

Twitter ranked second best for mobile-exclusive traffic, but the mobile numbers were no where close to Pandora's. With a total user populace of 56.7 million, Twitter's desktop users outpaced its mobile users 36.8 million to 30.6 million. It was the narrowest lead on the list of 30 companies.

The list's top three for total traffic--Google, Yahoo, and Facebook--still got far more traffic from desktop users than mobile. Top-ranked Google, for example, saw a user gap of more than 80 million between its mobile and desktop sites. 

According to Lipsman, these sites are slowly moving into the mobile realm because each one is still learning how to gain equal profits from both platforms.

"They're willing to experiment," Lipsman said. "But they're not willing to input dollars in big way until they know that the medium works for them."