Facebook Inc beat estimates for quarterly revenue on Wednesday and said it has seen “signs of stability” for sales in April after a plunge in March.

The company reported an 18% increase in first-quarter revenue, showing advertising demand was strong before the Covid-19 pandemic hit marketing budgets. The company also said business was steady in the first few weeks of April.

Facebook said advertising revenue was roughly flat in the first three weeks of April compared with the same period last year.

Ad sales, which make up nearly all of Facebook’s revenue, rose 17% to $17.44 billion.

Some businesses ran more ads after the pandemic wiped out Facebook ad pricing over the course of the quarter, contributing to a 39% increase in total ad impressions, executives said.

Chief Operating Officer Sheryl Sandberg told analysts the company saw an increase in gaming ads and steady spending from technology and e-commerce players, which offset “significant declines” in ads from the hard-hit travel and auto sectors.

However, a flat revenue in April indicates that the second quarter will be “more challenging” than the first.

Daily users of all Facebook’s apps, including Instagram and WhatsApp, averaged 2.36 billion in March, up from 2.26 billion in December, the company said. Facebook’s core social network now has 1.73 billion daily users, compared with 1.66 billion during the final month of 2019.

The company said around 3 billion users interacted with at least one of its apps each month in the quarter, up from 2.9 billion last quarter, as social networks use surged during coronavirus lockdowns. Some of that engagement is expected to slip once shelter-in-place orders are relaxed, it said.

Facebook lowered its guidance for total expenses in 2020 to $52 billion-$56 billion, down from a prior range of $54 billion-$59 billion, citing the slower headcount growth and savings from canceled travel, events and marketing.

Total costs for the first quarter rose just 1% to $11.84 billion.