YouTube has faced a number of controversies recently, but it appears they haven't affected its user growth. CEO Susan Wojcicki has announced that a massive 1.8 billion registered users are now watching videos on the site every month, and that figure doesn't include those who view content without logging in.

Wojcicki announced the updated viewer numbers at YouTube's Brandcast event for advertisers yesterday. Last year, the company said it had 1.5 billion viewers logging in and watching videos every month.

The CEO also announced some of the platform's notable success stories this year, including Despacito becoming the first video in YouTube history to pass 5 billion views last month, and Beyoncé's record-breaking livestream from Coachella, which was viewed by over 41 million users.

YouTube has had a rocky relationship with advertisers in recent times. Hundreds of them pulled their ads from the site last year after discovering they appeared on videos promoting hate speech and extremist content. This led to the company adding more requirements before allowing channels to display ads and share the profits. But last month saw more advertisements from major companies appearing on controversial videos.

Wojcicki used the event to bring up some of YouTube's other recent problems, including the increasing popularity of conspiracy theory videos on the site, and the appearance of inappropriate kids' videos.

"This is the impact of an open platform: it brings the world together in ways that were just not possible before. But we've also seen that with openness comes challenges, as some have tried to take advantage of our services," the CEO said. "It is incredibly important to me and to everyone at YouTube that we grow responsibly."

Wojcicki reiterated that YouTube would increase its number of human moderators to 10,000 by the end of the year, though it's not clear how large the team is today. The platform is also advancing its machine-learning systems to better identify offending content.