MyKindleをChromeで開いて、JSConsoleで実行すると日別の購入冊数が取得できるでござる。

gistfile1.js

(function(){
  var counter = {};
  var page = {now: 1, max: pageList.pages};
  var parseList = function(){
    var nodeList = $$('tr.rowHeaderCollapsed td.greyed');
    for(var i = 1; i < nodeList.length; i = i + 2){
      if(nodeList[i] != null){
	    	var ymd = nodeList[i].innerText;
  			if(!counter[ymd]){
  				counter[ymd] = 0;
  			}
  			counter[ymd]++;
    	}
    };
    if(page.now < page.max){
      page.now++;
      pageList.gotopage(page.now);
      setTimeout(function(){
        parseList();
      },1500);
    }
    else{
      var result  = '';
      var counter2 = 0;
      var keys = Object.keys(counter);
      for(var j = keys.length - 1; j > 0; j--){
        counter2 += counter[keys[j]];
        result   += keys[j] + "\t" + counter2 + "\n";
      }
      window.prompt("copy text", result);
    }
  };
  parseList();
})();

gistfile2.txt

// タイトル一覧
(function(){
  var page = {now: 1, max: pageList.pages};
  var parseList = function(){
    var nodeList = $$('tr.rowHeaderCollapsed span.headerTitle');
    for(var i = 1; i < nodeList.length; i = i + 1){
      if(nodeList[i] != null){
      		console.log(nodeList[i].innerText);
    	}
    };
    if(page.now < page.max){
      page.now++;
      pageList.gotopage(page.now);
      setTimeout(function(){
        parseList();
      },1500);
    }
    else{
    	alert('done');
    }
  };
  parseList();
})();