EngageSpark builds software to help companies reach clients and audiences through phone and SMS campaigns. Its clients can create phone surveys, pre-recorded messages, interactive telephone services, automatic replies in audio or text, and more. The idea is to reach people who aren’t online all the time, either because they don’t have the infrastructure or because they can’t afford mobile data plans.

EngageSpark launched in 2015 and since then has been able to acquire clients worldwide.

It cites a report (PDF link) by the UN’s Broadband Commission stating that 53 percent of the world’s population was still offline at the end of last year, while 1 billion people have smartphones but can’t afford regular data plans. That’s a lot of people who can only be reached by telephone or SMS.

The startup can offer those services without its clients needing to set up any kind of IT or telecommunications infrastructure. It even provides messages for Facebook Messenger.

At the same time, it builds APIs for customers that do have software teams of their own but whose core focus is perhaps not this type of communications tech.

EngageSpark launched in 2015 and since then has been able to acquire clients worldwide, including Facebook, Google, Intel, and UNICEF. Through its product, it promises access to a larger audience and increased engagement.

“This funding will help us scale our traction and platform to new markets,” says founder and CEO Ravi Agarwal in a statement. The startup will focus on more marketing and sales personnel and further development of its tech. It’s the first external funding the company has raised.

500 Startups managing partner Khailee Ng says that EngageSpark’s approach towards audiences in emerging markets impressed the investor. “We were early investors in Twilio and see EngageSpark’s potential in the same way,” he adds in a statement.