How to estimate ReadyAPI usage in my organization?

I suppose if you're usding ReadyAPI, then someone must know by the number of licenses.

If using SoapUI (free version), then I guess there's no way to find out.

we have ReadAPI test floating user subscription. 

Is it that when you are trying to use, you are getting no license available or something like that and you don't who is using it?

Or you want to know how many licenses you want to buy for your organization?

There might be some kind of communication / messaging tool, where you can take poll or something like that or some email alias etc with which one can obtain the details possibly.