Lots of websites have a comment section. Some sites which get huge numbers of comments have a sort of voting system for determining which comments are helpful, and which are not. The website of the San Francisco Chronicle is an example of such a site: this article on Oakland's use of ranked choice voting (AKA instant runoff voting) shows the system in action.
You'll note that, for each comment, you can give it a "thumbs-up" or a "thumbs-down", or leave it alone; the difference between ups and downs gives each comment a net score, and the most highly-scored comments get preferred listing. This is an example of range-3, i.e., range voting with three levels. Meanwhile, comment sections at The New York Times allow you to "recommend" comments, and the most-recommended comments get preferred listing. This is an example of approval voting, and is probably the most common sort of comment-voting setup on the internet.
However, I have never seen anywhere on the internet a comment-voting setup that used any sort of ranked-order voting system. (Although Kitten War comes close to a Condorcet system, sort of.) Why do you think that might be the case? Of course, who our next elected representatives will be is a much more important question than which is the most helpful blog comment (and obviously, when the stakes are so much higher, captchas and email-verification wouldn't be used for voter-roll identification) but the theory is the same: many people will have an opinion, and we want to aggregate those opinions to express a single, group opinion. If range and approval voting work so well in one domain, there's good reason to expect that it will work well in the other.