Could you please provide us with a url so that we can take a look at what's going on? That's the only way we can really diagnose any issues.
Now, just to make sure I'm understanding fully, you ask, "Is this a free program for the webmaster through WordPress or not?" In the backend, the only place you're going to see it is on actual comments. So if you go to the Comments menu along the left of your dashboard and then into a specific comment, you should see something like this:
As for showing on the front end, I'm not sure what eCommerce plugin you're using, but you're only going to see it on comment-able items such as pages and posts. It's not necessarily going to add the comment function to everything. But where you have comments available, you should see something like this:
The line just below "Logged in as..." is the Ajax Edit Comments options. If this isn't showing for you where comments are, you might try to test for a plugin conflict. So deactivate all plugins except for Ajax Edit Comments and see if it shows as it should. If it does, try reactivating your other plugins one at a time, checking your comments area each time, to see which one is creating the conflict.
Let me know if this helps or not. And if you give us a url, we can take a look for you.
Thanks,
Elise
