• by Gavin O'Malley  @mp_gavin, July 29, 2015

On the heels of a mixed earnings report, on Tuesday, Twitter lost another top executive.

Todd Jackson, the social giant’s director of product management, is headed for Dropbox. Jackson is joining the file hosting service as its first vice president of product. Jackson signed on to Twitter after it scooped up his mobile technology startup Cover last year.

“Excited for what’s next,” Jackson tweeted on Tuesday. “Joining [Dropbox] to lead product and work alongside an incredible team!”

Jackson is just the latest executive to depart Twitter, in recent weeks. Gabriel Stricker, Twitter’s longtime chief of communications, was recently sent packing.

Twitter’s problems -- which recently took down CEO Dick Costolo -- go beyond matters of product development and communication.

During the second quarter, the company’s earned an adjusted $0.07 per share on revenue of $502 million -- up 61% year-over-year, and above the previously forecast range of $470 million to $485 million.

Yet, during the period, Twitter added just 2 million new core users -- a figure that interim CEO Jack Dorsey called “unacceptable” on a Tuesday earnings call.

“In order to realize Twitter’s full potential, we must improve in three key areas: ensure more disciplined execution, simplify our service to deliver Twitter's value faster, and better communicate that value,” Dorsey said on Tuesday.

The vast majority of monthly active users added in the second quarter on a sequential basis came from “SMS Fast Followers.” Excluding that subset, MAUs were 304 million for the second quarter -- up only 12% year-over-year.