Taking a page from rival Twitter (NYSE: TWTR), Facebook (NASDAQ: FB) warned Tuesday it is seeing a slow down in advertising sales amid the COVID-19 outbreak. In a blog post, the social media giant said it is experiencing a huge uptick in usage in areas most affected by the pandemic but warned that won't be enough to cushion the blow from a weakening advertising business. IMAGE SOURCE: GETTY IMAGES. Facebook said that, in many of the countries hit hardest by the virus messaging has increased 50% during the month. In Italy, Facebook has seen a 70% increase in time spent across its apps, and views on Instagram and Facebook Live have doubled in a week. "We don't monetize many of the services where we're seeing increased engagement, and we've seen a weakening in our ads business in countries taking aggressive actions to reduce the spread of COVID-19," Facebook wrote in its COVID-19 update. Facebook's warning mirrors what Twitter had to say a day earlier. The microblogging operator cautioned that it wouldn't meet its guidance for the first quarter because of the COVID-19 pandemic. Like Facebook, noted its user base is growing, as people seek out information on social media. "The COVID-19 impact began in Asia, and as it unfolded into a global pandemic, it has impacted Twitter's advertising revenue globally more significantly in the last few weeks," said Ned Segal, Twitter's Chief Financial Officer in a press release providing the quarterly update. "We have made solid progress on our consumer and revenue product priorities and we remain confident in our opportunity and strategy." It's not clear if Alphabet's (NASDAQ: GOOG) (NASDAQ: GOOGL) Google will be the next to issue a warning about the current quarter. 10 stocks we like better than Alphabet (A shares)When investing geniuses David and Tom Gardner have a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* David and Tom just revealed what they believe are the ten best stocks for investors to buy right now... and Alphabet (A shares) wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of March 18, 2020 Suzanne Frey, an executive at Alphabet, is a member of The Motley Fool's board of directors. Randi Zuckerberg, a former director of market development and spokeswoman for Facebook and sister to its CEO, Mark Zuckerberg, is a member of The Motley Fool's board of directors. Donna Fuscaldo has no position in any of the stocks mentioned. The Motley Fool owns shares of and recommends Alphabet (A shares), Alphabet (C shares), Facebook, and Twitter. The Motley Fool has a disclosure policy.Source