Salesforce invested $100 million in Zoom's IPO, and it's paying off quickly, almost doubling in value in just three trading days.

It's the result of an unconventional investing approach for Salesforce Ventures. Like other corporate venture arms, Salesforce typically backs earlier-stage companies, but since early last year the venture group has been buying shares in select IPOs, like Dropbox and SurveyMonkey, hoping to benefit from the expected pop and to forge a tighter bond with emerging cloud software companies.

With Zoom, the company is working to enable live video for Salesforce's sales and service representatives and is integrating Salesforce's Einstein artificial intelligence technology to transcribe Zoom video meetings for participants, said John Somorjai, the head of Salesforce Ventures.

"It was a very basic integration and now will be much deeper," Somorjai said in an interview this week. "There are a lot of ways we can bring these products together."

Shares of Zoom rocketed 72% in their debut on Thursday and have continued to trade higher, closing on Tuesday at $69, valuing Salesforce's stake at about $192 million. But while Salesforce Ventures invested alongside traditional public market buyers, the company agreed to the same 180-day lockup period as insiders and even signed a so-called standoff agreement with Zoom not to sell the shares for up to a year, according to the prospectus.

"Our goal is to be long-term investors," said Somorjai, who is also Salesforce's executive vice president of corporate development.

Zoom is the third cloud software stock Salesforce has bought in an IPO, following Dropbox in March 2018 and SurveyMonkey in September. Both of those produced less dramatic returns. Salesforce's $100 million investment in Dropbox is now worth $111 million, and its $40 million initial stake in SurveyMonkey is valued at $58.5 million as of Tuesday's close.