Twilio ($TWLO) has reported its first quarter 2017 earnings, revealing that it generated $87.4 million in revenue, a 47 percent annual increase, with a non-GAAP net loss per share of $0.04.

Wall Street analysts had expected the company to report $83.6 million in revenue and a non-GAAP net loss per share of $0.06.

Shares in the company were down 1.34 percent for the day to close at $33.93. In after-hours trading, Twilio’s stock fell sharply more than 27 percent, largely due to weaker guidance — the company dropped its estimate for the full year from between $364 million and $372 million to $356 million to $362 million. Its non-GAAP net loss per share also fell from between $0.19 to $0.15 to $0.30 and $0.27.

The cloud-based telecommunications company continues to rack up customers: It now has 40,696 accounts as of March 31, 2017, a 42 percent year-over-year increase.

“We made continued progress across a number of our key initiatives in the first quarter, delivering further product innovation and adding new customers of all types at a rapid pace around the globe,” Twilio chief executive Jeff Lawson said in a statement. “While we are seeing some changes in the relationship with our largest customer, our momentum across the business continues to be strong, with a 42 percent year over year growth in Active Customer Accounts and a 62 percent year over year growth in Base Revenue during the quarter.”

In the past quarter, Twilio marked its achievements by bringing on a new chief operating officer, former Salesforce executive George Hu; launching a way to let you send and receive faxes; and extended its partnership with Amazon Web Services with new support for Amazon Connect.

Why Twilio’s guidance is less than previously expected is unknown, but hopefully Lawson will be able to answer that during the company’s quarterly earnings call, scheduled for later today.

Update as of 4:23 p.m. Pacific on Tuesday: Twilio has attributed its revised guidance to Uber reducing its usage of the platform.