DUBLIN -- The CEO of Slack, the hot tech startup with the eponymous workplace collaboration tool, says he has no desire to sell his company, but he might let it go for the right price. If someone offered $100 billion tomorrow, he says, he'd jump.

The $100 billion figure might seem ludicrous, but it's what investor John O’Farrell -- a partner at the venture capital firm Andreessen Horowitz and a Slack board member -- earlier this year said the company could be worth if CEO Stewart Butterfield "plays [his] cards right." At Web Summit in Dublin on Tuesday, Butterfield was asked what figure would make him consider selling his company, which was valued at $2.8 billion just six months ago. "I don't know what the threshold is, [but] if someone offered us $100 billion tomorrow, we'd probably take that."

Butterfield has experience in selling a startup for a lot of money, having sold Flickr to Yahoo over a decade ago for $25 million. At the time, that seemed like a lot of money, but in today's hyperinflated tech stock valuations, it's a pittance. "The prospect of selling my company for $25 million sounded like a lot of money. Now, the thing to me that sounds preposterous is the idea that $25 million isn't an insane amount of money."

In the tech world, where big acquisitions and mergers are relatively commonplace, Butterfield says the dance people do around such a buyout is never straightforward: "No ever comes and says, 'Hey, I'd like to buy your company for this much,'" Butterfield said when asked if he'd gotten any calls about buying Slack. "They say something like, 'If you would be interested in having a conversation about how our companies could work more closely together, I would also be interested in that conversation'."

While selling is an option, Butterfield says the Slack company culture and the service's fast pace of growth indicate an opportunity to build something big, and potentially reach that  $100 billion valuation: "There are so many things that had to come together for this to happen. We're clever and work hard, but we also had unbelievably lucky timing. We'll never have a chance like this again, so if we ever wanted to do something for ourselves, this is the time."