(Reuters) - Twitter Inc TWTR.N shares plunged more than 14 percent on Thursday after the social media platform disappointed investors with stagnant monthly active user growth in the second quarter.

Despite its appeal among celebrities and public figures, Twitter has struggled to sustain its closely watched user growth even as it invests in features and live content to help draw viewers and boost user engagement.

It is in stiff competition for advertising dollars with other platforms like larger rival Facebook Inc FB.O and Snap Inc’s SNAP.N messaging app Snapchat.

The company also reported a wider quarterly net loss and lower revenue, and said it did not expect its total revenue growth to pick up in the second half of the year.

Twitter had 328 million average monthly active users (MAU) in the three months through June 30, unchanged from the previous quarter. Analysts were expecting 328.8 million, according to financial data and analytics firm FactSet.

Shares had surged some 40 percent since mid-April as Twitter investors bet on another quarter of growth after the microblogging service reported adding 9 million more monthly active users than expected in the first quarter.

“If you really can’t accelerate MAU interest given the daily tweets from POTUS, not sure when you will,” said Michael Nathanson, senior research analyst of MoffettNathanson Research, referring to an acronym for the president of the United States.

U.S. President Donald Trump, one of the most active politicians on Twitter, has tweeted multiple times a day on average since his inauguration in January, according to social media analytics company Zoomph.

“The positive contributions to MAU growth from product improvements in the second quarter were offset by lower seasonal benefits and other factors, resulting in flat MAU quarter-over-quarter,” said Chief Operating Officer Anthony Noto during a conference call with analysts.

In the United States, Twitter’s average monthly active users fell to 68 million from 70 million in the first quarter.

Monthly active users, a key performance indicator for social networking services, is typically calculated by tabulating the number of users who have logged in and logged out during the 30-day period.

FILE PHOTO: People holding mobile phones are silhouetted against a backdrop projected with the Twitter logo in this illustration picture taken September 27, 2013. REUTERS/Kacper Pempel/Illustration//File Photo

Facebook on Wednesday had reported that its already massive user base continued to grow in the second quarter, with some 2.01 billion people using its service monthly as of June 30, up 17 percent from a year earlier.

By 1:54 P.M. ET (1754 GMT), Twitter shares were down 14.2 percent at $16.84, after falling as low as $16.50 and wiping out more than $2 billion in market value.

HEADWINDS

Twitter’s second-quarter net loss widened as it took a $55 million impairment charge related to an investment writedown and revenue fell 4.7 percent.

The company has been trying to boost revenue through live-streaming deals, but had a setback in April when it lost a deal to stream U.S. National Football League games this year to Amazon.com Inc AMZN.O.

Advertising revenue fell 8 percent to $489 million, but well exceeded the $458.1 million estimate.

Twitter’s net loss widened to $116.5 million, or 16 cents per share, in the second quarter ended June 30, from $107.2 million, or 15 cents per share, a year earlier.

Excluding items, the company earned 8 cents per share.

Revenue fell to $573.9 million, the second time it has fallen since Twitter’s market debut in 2013.

Analysts on average expected a profit of 5 cents per share, and revenue of $536.62 million, according to Thomson Reuters I/B/E/S.

“They (revenue and profit) are still unimpressive, and the ‘beat’ was because they set very low expectations,” said Michael Pachter, managing director at Wedbush Securities.

Twitter said in a letter to investors that the company does not expect its total revenue growth rate to improve in the second half of 2017 “due to headwinds in the second half (of approximately $75M) associated primarily with de-emphasized revenue products.”

But the company said it is looking to data licensing, which it claims is its fastest-growing product area, to turn around revenue in the future.