"Weebly was started in 2007 and currently powers more than 50 million entrepreneurs around the world"

https://www.crunchbase.com/organization/weebly#section-overv...

The TechCrunch article about the deal says they have 625,000 paid subscribers https://techcrunch.com/2018/04/26/square-acquires-weebly/

Ok. Assuming that number has any merit, it'd be "websites built with Weebly". If we take a page from WiX's book, divide by 10^2 to get paying customers.

From Weebly's about page: "More than 325M unique visitors are now going to over 40M Weebly sites monthly."