'I have never, ever seen anything like this' - Kevin O'Leary says Twitter rival Threads is showing unprecedented growth

• Kevin O'Leary praised user growth on Meta's new Threads app, which seeks to take on Twitter.
• Over the weekend, the platform's sign-ups topped 100 million after launching on July 5.
• "I have never, ever seen anything like this," O'Leary told CNBC on Monday evening.

The new Meta Threads app is seeing rapid user growth, drawing the attention of "Shark Tank" star Kevin O'Leary.

On Monday, Meta founder Mark Zuckerberg wrote in his own Threads feed that the app reached 100 million sign-ups over the weekend after launching days earlier on July 5.

"I have never, ever seen anything like this," O'Leary told CNBC on Monday evening. "This is unprecedented and it's not even in Europe yet, and we sell in Europe. This thing — and I'll say it again — is on fire."

Functioning as part of the company's Instagram platform, Threads allows users to write and share text posts of up to 500 characters. It's similar to Elon Musk's Twitter, which has since threatened to sue Meta over the app.

With Threads' growing audience, O'Leary predicted that small businesses will eventually be seeing higher returns on ad expenditures.

"If it can help us drive down CAC — which is customer acquisition cost — and increase our return on advertising spend past two times, we're all over it," he said. "We go where the eyeballs go."

O'Leary also praised Zuckerberg for maintaining focus across his social-media sites on storytelling. "These platforms are remarkably good at allowing small businesses to tell the story of their product or service."

Meanwhile, Twitter has had problematic relations with its advertisers, many of whom left the platform when Musk took over in October 2022. A recent report showed that the company lost 59% of its ad sales in a year.