Opal Labs CEO Steve Giannani.

Given its early-stage investments in companies like Facebook, Slack, and Dropbox, if your company raises money from Accel, it’s probably a good sign.

Opal, a marketing collaboration startup based in Portland, today announced a $15.5 million Series B round led by Accel, the 34-year-old Silicon Valley venture capital firm, along with participation from existing investors Madrona Venture Group, Seven Peaks Ventures, and MMC Ventures.

GeekWire reported on the funding back in December, but now we have more details about how Opal will use the fresh cash and the investors involved.

Founded in 2011, Opal has quietly built a market-leading company that helps businesses streamline the production of marketing and media campaigns with one central platform and framework. Clients include NASA, Nike, Starbucks, Target, Airbnb, and others.

A 2013 graduate of the Portland Seed Fund, Opal bootstrapped in its early days before raising a $2.1 million seed round led by Oregon Angel Fund. In 2014, it raised an $8 million Series A round led by Seattle-based Madrona. Total funding in the company is now $25.6 million.

This Series B round marks a pivotal milestone for the company as it looks to establish itself as the top platform of choice for companies that want to streamline their brand marketing process across every consumer touch point.

“We want to accelerate growth and solidify our position as a market leader…