San Francisco-headquartered Intercom is to create 100 new jobs in Dublin after raising $50m in investment from top-tier Silicon Valley investors, including Slack CEO Stewart Butterfield.

Index Ventures’ Ilya Fushman led the round, with participation from previous investors Iconiq Capital, Bessemer Venture Partners and Social Capital, as well as participation by Slack founder Stewart Butterfield and Basecamp CEO Jason Fried. Intercom was founded in San Francisco by four Irishmen – Des Traynor, Ciaran Lee, Eoghan McCabe and David Barrett – but most of the company’s technology is made in Dublin where the company currently employs 140 people at its offices on St Stephen’s Green. Worldwide, Intercom employs 250 people.

The latest investment comes just months after Intercom raised $35m last August, announcing plans to double its Dublin workforce. The company says it now has 10,000 paying customers in over 90 countries, up from 5,000 in April 2015, ranging from start-ups like Expensify and Trunk Club to public companies like Rackspace and IBM.

Intercom is understood to have grown revenues fourfold into the tens of millions of dollars, and will use the funds to continue investing heavily in new and existing products on the Intercom Platform. Most companies at Intercom’s stage spend less than 50pc of revenue, and have less than 30pc of headcount working on new product development.

Last year, Intercom spent 85pc of its revenue, and had 50pc of its headcount, on R&D. “At Dropbox, we were always looking for ways to improve how we talked with customers,” said Ilya Fushman, general partner at Index Ventures and former head of product at Dropbox. “A single platform to communicate with our customers throughout their lifecycle would have been our Holy Grail—and that’s Intercom. Along with solving this fundamental problem, their relentless focus on the end user and consistent investment in building the best product possible have led to their rapid and highly-efficient growth as a business.”