Zendesk Inc., which makes software aimed at managing long-term relationships with customers, on Thursday said it’s adding another platform to its toolbox by acquiring Outbound.io Inc.

Founded in 2013, Outbound.io is a Y Combinator-backed startup that provides a customer service messaging system with a strong focus on reaching customers through their mobile devices. Outbound.io’s platform manages messaging campaigns that can reach people throughout various stages of of the customer journey, but the company’s founders said simply pestering customers with messages is not enough to get them the help they need or encourage them to complete a transaction.

“As end users become increasingly overwhelmed by the volume of automated messages they receive, message quality has become a differentiator and driver of long-term customer relationships,” Outbound.io founders Dhruvkaran Mehta and Josh Weissburg said in a blog post announcing the acquisition by Zendesk. “The core functionality that Outbound offers—better message targeting and timing, more flexible and dynamic content across channels, and deeper A/B testing—gives marketing and product teams new forms of feedback on the effectiveness of the messages they send.”

Mehta and Weissburg said Outbound.io will continue to exist as a separate platform, and existing customers can continue using it as usual, but the platform will now be sold as a product of Zendesk. The Outbound.io founders said they will use Zendesk’s knowledge and resources to improve their platform, and they will also be adding integrations with Zendesk’s other products.

Adrian McDermott, Zendesk’s president of products, said that Zendesk first met with Outbound while exploring a potential partnership for a specific customer.

“Through this process, we observed that Outbound’s philosophy of ‘fewer, better messages’ aligns well with our vision at Zendesk — helping businesses have authentic, sustainable relationships with their customers through beautiful, intuitive software experiences,” McDermott said. “Today’s customer expects businesses to know more about them, to engage with them in a more personal way, and to engage with them when and how they prefer. In turn, today’s businesses are looking to be more data-driven, more responsive, and more authentic as they market, sell to, and support their customers.”

The two companies did not disclose the terms of the deal.

Photo: Paul Jacobson Annabella’s birthday party-113 via photopin (license)