We charge a monthly service fee based on web traffic. No free tier at the moment. Send me a note at ryan@rankscience.com if you'd like to learn more!
I did email you... no response.
It really would have been helpful if you'd just shared it here so others could see as well!
Just replied :)
I've just checked my email and spam folder and it appears you haven't. My email was from six days ago, subject line "pricing" and the body includes "I asked on HN"...