Microsoft Office 365 is used by one in 13 small and medium sized business in the US, cloud management company SkyKick said in its State of the Office 365 SMB Cloud report, released on Wednesday, which shows a major market opportunity for SMB service providers.

Larger businesses are more likely to use Office 365, the report said. While 7.5 percent of SMBs use Office 365 overall, 16.6 percent of businesses with 51-250 employees use it, and only 5.6 percent of offices with under 10 people do.

“SkyKick’s State of the Office 365 SMB Cloud research shows the shift to cloud is definitely underway and there’s a big opportunity ahead for the industry,” said SkyKick co-CEO Todd Schwartz. “For many businesses the shift to the cloud begins with Office 365, so we’re providing Office 365 adoption insights to help partners focus on capturing their piece of the projected $500 billion cloud market. Our goal with this research is the same as our products and mission—to help IT solution providers be more successful in the cloud.”

By industry vertical, Office 365 is most common among industrial SMBs, with over 30 percent of coal mining companies using the Microsoft product, while fewer white collar business services like insurance carriers (13.5 percent) use it than tech-focussed business services.

The report also breaks down Office 365 SMB adoption by state.

Office 365 is the most used web-based business application overall, according to a report published by Okta in March, which also showed that the average organization uses 13 cloud apps.