It is a difficult question to answer, since you do not need to register to use the script. Upon installation or first run, the script makes a request to my webserver for a file (either an image or a script). I keep track of those requests.

This is the information I have for 2014, for installations from Greasy Fork, OpenUserJS, and userscripts.org combined:

1/1/2014-3/31/2014: estimated 405 new and upgrade installations

4/1/2014-6/30/2014: estimated 456 new and upgrade installations

Obviously the installation count for the script on this site is seriously inflated.

Re: @jscher2000:
Keep using! Thanks for all the efforts.
It seems that the script is down recently. I'm using Chrome v41, not sure if it's a browser issue.

Re: @sobasin:
Hmm, sorry, I don't check for replies every day.

What do you mean by "down"?

Does the script appear to be enabled normally on the Tampermonkey dashboard?

Is it working on other supported sites like https://startpage.com/ or https://duckduckgo.com/ or http://www.bing.com/ or not working on any site?