• by Gavin O'Malley  @mp_gavin, August 26, 2014

Twitter on Tuesday further expanded its ad network with the addition of 12 markets in Central and Eastern Europe, as well as Portugal.

Austria, Switzerland, and Croatia have been added, along with Ukraine, Bosnia & Herzegovina, Bulgaria, Czech Republic, Macedonia, Romania, Serbia, and Slovenia.

According to the micro-blogging giant, it has recently experienced big growth in that part of the world. "There has been tremendous growth in this region over the last year,” Ali Jafari, Twitter’s vice president, direct sales in Europe, boasted in a Tuesday blog post.

Per these most recent additions, the Twitter Ads program will now be available in 35 EMEA (Europe, Middle East and Africa) markets through direct sales support teams and reseller partnerships.

Along with geographical expansion, Twitter continues to invest in improvements to its ad services, including the launch of its Promoted Video program -- which helps brands more easily upload, distribute, and track video throughout its network -- and its so-called “objective-based” campaigns and pricing service.

While user engagement and growth remain concerns for investors, Twitter’s advertising and media strategies appear to be thriving. Last month, the company reported second-quarter results that safely exceeded Wall Street expectations. In fact, revenue soared 124% to $312 million, while monthly active users increased 24% to 271 million.

During the second quarter, ad revenue grew 129% from a year ago to $277 million, while mobile ads accounted for 81% of the total. 

Industrywide, Twitter accounted for 0.5% of global digital ad revenues in 2013, according to eMarketer -- a figure the research firm expects to increase to 0.8%, this year. Stateside, eMarketer estimates that digital advertising will reach $50.71 billion in 2014, with Twitter taking a 1.5% share -- up from its 1% share, last year.

By the critical measure of time-spent, however, Twitter appears to be struggling.

Along with Instagram, WhatsApp, and Snapchat, Twitter saw its domestic share of mobile minutes (smartphones only) decrease from 5.1% to 4.7%, in July. That’s according to recent findings from JPMorgan, which was based on comScore data.

By contrast, Facebook’s domestic share of mobile minutes appeared to remain stable at about 20%, last month.