The Home Depot said today it is catching on with professional customers, as the big-box retailer reported its greatest customer improvement during the second quarter occurred in the pro sector. Company executives did not specify just how big of an improvement it was compared with other sectors.

Marvin Ellison, executive vice president of U.S. stores, said the company's net promoter score, which is a measure of how likely a customer is to recommend Home Depot to others, rose 270 basis points. Ellison also said the company shortened wait-to-checkout times and made loading easier for professional customers.

"We feel really good about pro and good about the service we put in pro," said Ellison.

This is the second quarter that the company has operated its "First for Pro" initiative, which is designed to better serve professional customers, and includes new hours, more point-of sales staffing, specialty parking for pros, more loading assistance, and easier product returns.

The program is the latest effort by The Home Depot to reach out to professional customers; a group that The Home Depot has said includes professional builders and remodelers as well as maintenance managers and other folks who get paid to keep up buildings. The company says about 4% of its customers generate about one-third of the company's sales.

"We did a lot of surveys of key pro customers to understand what they wanted, from a retail look, to serve them," Ellison said. "The key for us is to engage our customers and understand what they're working on."