Adwerx, a digital marketing company primarily for the real estate market, sold $4.4 million in shares in a private stock offering, according to a Securities and Exchange Commission filing on Tuesday.

The company filed the form D on Aug. 29. It did not disclose what it intended to do with the proceeds.

Adwerx began in 2013 and allows real estate professionals to advertise new listings, generate demand for older listings and build their online brand. It has over 40,000 real estate customers across all 50 states and Canada.

It has since expanded its digital advertising offerings to include dental practices, law offices, restaurants, salons and spa, among other businesses.

The company is led by Chief Executive Officer Jed Carlson, a Duke MBA graduate. He previously worked at American Spirit Graphics and ReverbNation.com.

Adwerx was spun out of ReverbNation, a champion for independent musicians co-founded in 2006 by Carlson, in January 2015.

Its Adwerx Quick Adder software was nominated for an Inman Innovation Award earlier this year.

Companies relying on a Reg D exemption do not have to register their offering of securities with the SEC, but they must file what’s known as a Form D electronically with the SEC after they first sell their securities.

The form can be found here.