Here's an updated example that uses the newer localStorage API instead of cookies to store the bookmarked page:

<script>
  function setBookmark() {
    // Save the current page URL to localStorage
    localStorage.setItem("bookmark", window.location.href);
    alert("Page bookmarked!");
  }

  // Check if the bookmark is saved in localStorage, and display a message to the user
  var bookmark = localStorage.getItem("bookmark");
  if (bookmark) {
    alert("You have bookmarked this page: " + bookmark);
  }
</script>

<a href="#" onclick="setBookmark()">Bookmark this page</a>

In this example, we use the localStorage API to save the bookmarked page URL instead of using cookies. The localStorage API provides a simple way to store data on the user's browser that persists even after they close the browser window.

We define a setBookmark() function that saves the current page URL to localStorage and displays an alert to confirm that the page has been bookmarked. We also check if the bookmark is already saved in localStorage when the page loads, and display a message to the user if it is.

The link to bookmark the page calls the setBookmark() function when clicked.

Note that this example uses the localStorage API, which is supported by most modern browsers. However, if you need to support older browsers, you may need to use a polyfill or fallback approach that uses cookies or other storage mechanisms.

<script>
  function setBookmark() {
    // Set a cookie with the current page URL
    document.cookie = "bookmark=" + encodeURIComponent(window.location.href);
    alert("Page bookmarked!");
  }
  
  function getBookmark() {
    // Get the value of the bookmark cookie
    var cookies = document.cookie.split(';');
    for (var i = 0; i < cookies.length; i++) {
      var cookie = cookies[i].trim();
      if (cookie.indexOf('bookmark=') == 0) {
        return decodeURIComponent(cookie.substring('bookmark='.length));
      }
    }
    return null;
  }
  
  // Check if the bookmark cookie is set, and display a message to the user
  var bookmark = getBookmark();
  if (bookmark) {
    alert("You have bookmarked this page: " + bookmark);
  }
</script>

<a href="#" onclick="setBookmark()">Bookmark this page</a>

In this example, we define two functions: setBookmark() and getBookmark(). setBookmark() sets a cookie with the current page URL when called, and getBookmark() retrieves the URL from the cookie.

We then create a link that calls the setBookmark() function when clicked. When the link is clicked, the cookie is set and an alert is displayed to confirm that the page has been bookmarked.

Finally, we check if the bookmark cookie is set when the page loads, and display a message to the user if it is.

Note that this example uses a simple approach to store the bookmark URL in a cookie, which may not be suitable for all use cases. You may want to consider other approaches, such as using browser storage or server-side storage, depending on your needs.

<style>
  .floating-ad {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background-color: #fff;
    border: 1px solid #ddd;
    padding: 10px;
    display: none;
  }
</style>

<div class="floating-ad">
  <a href="#" target="_blank">
    <img src="/ad-1.png" alt="Ad 1">
  </a>
</div>

<script>
  var ads = [
    {
      imageUrl: 'ad-1.png',
      linkUrl: 'https://example.com/special-offer-1'
    },
    {
      imageUrl: 'ad-2.png',
      linkUrl: 'https://example.com/special-offer-2'
    },
    {
      imageUrl: 'ad-3.png',
      linkUrl: 'https://example.com/special-offer-3'
    }
    // Add more ads here as needed
  ];
  
  var randomAdIndex = Math.floor(Math.random() * ads.length);
  var ad = ads[randomAdIndex];
  
  var randomTime = Math.floor(Math.random() * 60000) + 60000; // Random interval between 1 and 2 minutes
  setTimeout(function() {
    var adElement = document.querySelector('.floating-ad');
    adElement.querySelector('img').src = ad.imageUrl;
    adElement.querySelector('a').href = ad.linkUrl;
    adElement.style.display = 'block';
  }, randomTime);
</script>

In this example, we have an array of ads that includes the URLs of the image and the link for each ad. We then use JavaScript to randomly select an ad from the array, and set the image and link for that ad in the floating ad element.

You can add more ads to the array as needed, and customize the ad image and link URLs to match your website's offers. Note that this is a basic example and you may want to consider other factors, such as the size and placement of the ad, to optimize its effectiveness.

Here's an example of a simple random floating click-through ad for your website:

<style>
  .floating-ad {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background-color: #fff;
    border: 1px solid #ddd;
    padding: 10px;
    display: none;
  }
</style>

<div class="floating-ad">
  <h3>Don't miss out on our special offer!</h3>
  <a href="https://example.com/special-offer" target="_blank">Click here to learn more</a>
</div>

<script>
  var randomTime = Math.floor(Math.random() * 60000) + 60000; // Random interval between 1 and 2 minutes
  setTimeout(function() {
    document.querySelector('.floating-ad').style.display = 'block';
  }, randomTime);
</script>

In this example, the ad is a simple text message with a call-to-action link. The ad is positioned in the bottom right corner of the page using CSS, and set to display at a random interval between 1 and 2 minutes using JavaScript's setTimeout() function.

You can customize the ad text, link, and styling to match your website's branding and design. Note that this is a basic example and you may want to consider other factors, such as the placement, size, and frequency of the ad, to optimize its effectiveness.