• by Gavin O'Malley  @mp_gavin, October 27, 2014

In line with analysts’ expectations, Twitter saw revenue rise to $361 million in the third quarter -- up 114% year-over-year -- the company reported Monday. Yet, user growth -- and a fourth-quarter revenue forecast of $440 to $450 million -- fell short of analysts’ hopes.

While insisting that Twitter remains on the right track, CEO Dick Costolo told analysts on Monday that it is “more critical than ever that we increase the pace of [product and idea] execution.”

For the quarter ended September 30, ad revenue totaled $320 million -- an increase of 109% year-over-year. Mobile ad revenue represented 85% of total ad revenue.

During the quarter, Twitter recorded 284 million average monthly active users (MAUs), which represented an increase of 23% year-over-year, but just 5% quarter-over-quarter.

Timeline views reached 181 billion during the quarter -- an increase of 14% year-over-year. Stateside, however, Timeline views per monthly active user actually fell from 793 to 774, quarter-over-quarter.

Advertising revenue per thousand timeline views reached $1.77 -- an increase of 83% year-over-year.

Among other efforts, Twitter just rolled out a new developer platform called “Fabric,” which provides a suite of tools to make it easier for programmers to build and distribute apps.

By providing a “foundation” for developer initiatives, Costolo said Fabric -- in unison with its MoPub ad-serving platform -- presented “enormous” monetization opportunities.

Twitter also launched a number of new ad tools during the period, including a Promoted Video beta; a “Buy” button for users to complete purchases directly from tweets; and objective-based campaigns, reports and pricing.

Twitter also launched an update to the profile experience on the iPhone with an increased focus on bios, tweets and photos. The change resulted in an 83% increase in profile impressions on iOS, Twitter reported on Monday.

Among other partnerships announced during the quarter, Twitter teamed with the NFL to better engage fans. In the #NFL Timeline, users can see NFL-related Tweets from people in their network, along with relevant Tweets from teams, players, coaches, press, fans and celebrities.

Beyond the U.S. market, Twitter continued the expansion of Twitter Ads to 12 additional markets in Central, Continental and Eastern Europe. In addition, Twitter entered 12 new countries with its self-service ad products for small- and medium-sized businesses, including Mexico, France, Italy, and the Netherlands.

Twitter’s self-serve ad products now serve marketers in 20 countries that in aggregate, account for more than 45% of its global monthly active user base.

During the past quarter, Twitter closed the acquisitions of CardSpring, a payments infrastructure company, TapCommerce, a provider of mobile retargeting and re-engagement ad services, and SnappyTV, a platform for video editing and distribution.