• by Gavin O'Malley  @mp_gavin, June 30, 2014

After what it considers to be a successful national test, Twitter is expanding its mobile app promotion ads worldwide.

The ads in question direct users to download new apps, or use apps they already have on their smartphones.

“Mobile app promotion leverages Twitter’s existing powerful targeting capabilities, including interest, keyword, TV targeting and tailored audiences to help [app publishers] reach [a] desired audience,” Kelton Lynn, a product manager at Twitter, explained in a Monday blog post. Publishers “can also layer on gender, geo, language and mobile platform targeting to pinpoint the users who are best suited for [their app,” according to Lynn.

Twitter first debuted its app promotion ads in April, which initially includes the option to buy Promoted Tweets designed to drive installs, as well as running campaigns outside Twitter through the company’s MoPub mobile ad exchange.

Once app promo ads are up and running, Twitter offers publishers conversion tracking, which lets them measure the “conversion impact” of their campaigns, including initial installs and in-app conversion events. To better measure the unit’s performance, Twitter relies on a number of mobile measurement firms, including Adjust, AD-X, AppsFlyer, Fiksu, Grab, Hasoffers and Kochava.

Also on Monday, Twitter debuted a new “cost-per-app-click” pricing and prediction model for the units and a new dashboard to track user engagement. Publishers are only charged when users click to go to the App Store or Google Play from their ad, or when they open their app directly from Twitter.

Social media marketers applauded Twitter’s expanded app advertising efforts, on Monday.

“It’s incredibly important for app developers and clients to get exposure for these mobile apps,” said Max Kalehoff, senior vice president, marketing at SocialCode, a Twitter marketing platform partner. “With so much competition in the app stores, having the ability to drive a large user base straight to download from their Twitter feed is a huge advantage.”

Adding to its ad offerings, Twitter recently agreed to buy Namo Media and pair their respective native advertising technology. The addition of Namo followed Twitter’s acquisiton of MoPub, last October.

Stateside, social media advertising revenues will grow from $5.1 billion in 2013 to $15 billion in 2018 -- representing a compound annual growth rate (CAGR) of 24%, according to a recent forecast from BIA/Kelsey.

From 2013 through 2018, social display ad revenues are expected to grow from $3.3 billion to $5.6 billion, representing a more modest CAGR of 11.3%. During the same period, however, U.S. native social advertising will surge from $1.8 billion to $9.4 billion, representing a CAGR of 38.6%. As such, the research firm expects native social advertising to eclipse social display for the first time by 2015.

Most of the credit goes to Facebook’s News Feed ads and Twitter’s Promoted Tweets, according to BIA/Kelsey. Driven by Facebook and Twitter, U.S. social mobile ad revenues eclipsed $1.5 billion in 2013. U.S. social mobile ad revenues will reach $7.6 billion by 2018, representing a CAGR of 38.3%.