Casey Newton:

With Facebook under antitrust scrutiny around the world, the company is spending more time making the case that it is beset on all sides by competitors. There are other messaging apps, other professional networking apps, and other video apps. And when it comes to good old-fashioned social networking — public broadcasts, following influencers, and that sort of thing, there’s TikTok.

“In just three years, TikTok has become one of the world’s most popular online social network platforms,” Facebook wrote today in a letter to Rep. David Cicilline, D-RI, who has championed an antitrust inquiry into the company. “The app has been downloaded more than one billion times globally, is available in more than 150 countries, and in 2018 was installed more times than either Facebook or Instagram.”

TikTok’s ubiquity is all the more striking considering that it just celebrated its first birthday on August 2nd. That’s when the Chinese company ByteDance, which had bought an American app named Musical.ly in November 2017, rebranded it as TikTok. In the year since, the app has become a global hit, thanks to a core feed powered by machine learning that’s entertaining even if you never follow anyone. (TikTok’s “duets” feature, which allows you to easily remix others’ content, also skillfully married a strong creative tool with a useful engagement hack.)