But the social network’s advertising revenue grew 18.4% during the quarter.

Twitter Inc. is still struggling to figure out what it wants to be when it grows up.

While the social network generated $535 million in advertising revenue in the second quarter, an 18.4% gain from the same period a year earlier, it added only 3 million new users during the quarter. To drive more consumers to its platform it has recently made a robust push to add content. For example, earlier this month it announced plans to stream Pac-12 college sporting events and to offer original live NBA programming.

“What makes our audience growth this quarter notable is we can see directly the link between the product changes we made and our growth,” said CEO Jack Dorsey during a conference call with analysts. “We’re making the right decisions in our products, and it gives us a foundation for future growth. We’re working every day to make Twitter faster, more intuitive, and easier to use. You’ve already seen us take some big steps here, like the changes to the timeline, and the announced changes to the character account and reply rules. And there’s more changes like these on the way.”

The changes have produced some tangible results. For instance, Twitter’s ads are growing increasingly valuable for retailers and other advertisers. The social network reports that ad engagements during the quarter rose 226% and the cost per engagement fell 64%.

For the second quarter ended June 30, Twitter reported:

  • $602.0 million in total revenue, up 19.8% from $502.4 million a year earlier.
  • $535 million in ad revenue, up 18.4% from $452 million.
  • Mobile advertising accounted for 89% of advertising revenue, or about $476.2 million.
  • 313 million monthly active users, up 3.0% from 304 million in the same period a year earlier, and up 1.0% from 310 million in the first quarter.
  • $107.2 million net loss compared with a $136.7 million loss a year earlier.

For the first half of the year, Twitter reported:

  • $1.196 billion in total revenue, up 27.5% from $938.3 million a year earlier.
  • $1.066 billion in ad revenue, up 26.9% from $840 million.
  • $186.9 million net loss compared with a $299.1 million loss a year earlier.