Twitter Inc (NYSE:TWTR) shares plummeted more than 10 percent on Thursday after the microblogging service announced its slowest quarterly revenue growth since its IPO in 2013. Revenue for the fourth quarter increased just 1 percent to $717.2 million that missed analysts’ average forecast of $740.1 million.

Revenue from advertising fell year-over-year to $638 million amid intense competition from Snapchat and Facebook. Twitter said ‘’advertising revenue growth may be further impacted by escalating competition for digital ad spending and Twitter’s re-evaluation of its revenue product feature portfolio, which could result in the de-emphasis of certain product features.”

The San Francisco-based social network reported net loss of $167.1 million, or 23 cents a share in the latest quarter ended Dec. 31, well above $90.24 million, or 13 cents a share, in the year-earlier quarter. On an adjusted basis, the company posted earnings of 16 cents per share that surpassed consensus forecast of 12 cents a share.

Twitter’s user base surged 4 percent to 319 million average monthly active users in the fourth quarter. Analysts on average were looking for 319.6 million monthly active users.