Twitter is expected to generate more advertising revenue next year than previously forecasted based in part on how quickly marketers are embracing mobile advertising on the social network, according to eMarketer.

In September, eMarketer forecast that Twitter would earn just more than $800 million next year from mobile advertising in 2014. However, with advertisers showing more interest in spending money on mobile advertisements on Twitter, eMarketer has revised to estimate upwards to $950 million.

?Marketers are spending more on mobile advertising on Twitter and the simple reason is that Twitter?s user base is shifting very quickly from desktop to mobile,? said Clark Fredricksen, vice president of communications at eMarketer, New York .

?Twitter has been very smart in creating ad experiences that would work well across any device,? he said. ?The reason is because the ads are integrated into the core user experience of the timeline.

?Now as advertisers start to spend more on mobile as Twitter?s user base becomes increasingly mobile, we are starting to see that early move come to fruition.?

Deep integration
Also driving Twitter?s expected growth in advertising revenue over the next couple of years are recent audience figures analyzed by eMarketer that suggest Twitter's reach is improving.

There are several other factors driving Twitter?s growing success in mobile advertising.

First, marketers are increasingly aware of the potential of mobile advertising thanks to the strong focus from companies such as Google and Facebook on the opportunities in mobile, with Twitter benefitting as a result.

Twitter has also launched an Ads API, which will contribute to incremental growth this year.

The social media company is also benefitting from the fact that its ad products are more deeply integrated into the core user experience, allowing companies to deliver similar ads across multiple devices at high volume. Twitter has been able to quickly build its mobile ad business as a result of this deep integration.

Incremental growth
EMarketer estimates that Twitter will earn $582.8 million in global ad revenue in 2013, with 53 percent of ad revenue coming from mobile advertising, up from virtually no ad revenue from mobile in 2011.

Mobile is expected to drive the most incremental growth over the next two years for Twitter. As a result, more than 60 percent of Twitter?s expected $1.33 billion in worldwide ad revenue in 2015 will come from mobile advertising.

Twitter's mobile Internet ad revenues worldwide are forecasted to reach $308.9 million this year, up 123 percent. In 2014, mobile ad revenues are expected to grow by a slightly more moderate 78.4 percent for a total of $551 million and by 2015, mobile ad revenues will reach $811.3 million, up 47 percent.

U.S. drives growth
Growth in mobile ad revenues will outpace Twitter's overall ad revenues, which are expected to reach $582.8 million this year, up 102 percent from last year.

Growth will slow somewhat over the next couple of years, with Twitter ad revenues expected to reach $950 million in 2014, up 63 percent, and $1.3 billion in 2015, hiked 40 percent.

Other key findings are that while the bulk of Twitter's ad revenue is expected to continue to come from the United States ? about 83 percent this year, down from 90 percent in 2012 ? continued expansion of foreign sales operations is expected to help non-U.S. ad revenue reach $319 million by 2015, up from just under $100 million this year.

One of the challenges that Twitter faces as it looks to derive revenue from mobile is that its user base is still relatively small.

?Twitter has highly engaged active users but both Google and Facebook have over 1 billion people using their platforms and Twitter is much smaller than that,? Mr. Fredrickson said.

Final Take
Chantal Tode is associate editor on Mobile Marketer