A Tampermonkey userscript to display some stats on AO3: the percentage of all visitors (hits) that left a kudo, comment, or bookmarked the story.

ao3_stats.js

// ==UserScript==
// @name         AO3 Stats
// @namespace    http://tampermonkey.net/
// @version      1.0
// @description  display ao3 stats
// @author       mxamber
// @match        https://archiveofourown.org/works/*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    var kudos_elem = document.querySelector("dl.stats dd.kudos");
    var kudos;
    if(typeof(kudos_elem) != 'undefined' && kudos_elem != null) {
        kudos = kudos_elem.innerHTML;
    } else {
        kudos = 0;
    }

    var comments_elem = document.querySelector("dl.stats dd.comments");
    var comments;
    if(typeof(comments_elem) != 'undefined' && comments_elem != null) {
        comments = comments_elem.innerHTML;
    } else {
        comments = 0;
    }

    var bookmarks_elem = document.querySelector("dl.stats dd.bookmarks > a");
    var bookmarks;
    if(typeof(bookmarks_elem) != 'undefined' && bookmarks_elem != null) {
        bookmarks = bookmarks_elem.innerHTML;
    } else {
        bookmarks = 0;
    }

    var hits_elem = document.querySelector("dl.stats dd.hits");
    var hits;
    if(typeof(hits_elem) != 'undefined' && hits_elem != null) {
        hits = hits_elem.innerHTML;
    } else {
        hits = 0;
    }

    console.log("hits: " + hits + ", comments: " + comments + ", kudos: " + kudos);

    var box = document.createElement("div");
    box.setAttribute("style", "font-size: 14px; z-index: 50; padding: 1em; border-radius: 0 0.5em 0.5em 0; border: 1px solid black; border-left: none; box-shadow: 0.5em 0.5em 1em rgba(0,0,0,0.5); color: black; background: rgba(255,255,255,0.7); position: absolute; top: 50vh; left: 0px;");
    box.innerHTML = "<p>Kudos: " + Math.floor(kudos/hits * 10000)/100 + "%</p>";
    box.innerHTML += "<p>Comments: " + Math.floor(comments/hits * 10000)/100 + "%</p>";
    box.innerHTML += "<p>Bookmarks: " + Math.floor(bookmarks/hits * 10000)/100 + "%</p>";
    document.body.appendChild(box);
})();