help me on this wordpress coding please..

hi everyone,
i need to put a personalized text somewhere after the post content but before the comments area. can anyone help me on this as to where should i put this piece of text?
this is some text that i want to put to promote a clickbank product.
my site is here :aboutwow.net
i have try on different areas of the code but can't figured out where is the correct place to put this text. pls help me... thank you..

Single Post (single.php)

<?php get_header(); ?>
<div id="wrapper">
<div id="content">


<?php if (have_posts()) : while (have_posts()) : the_post(); ?>



<div class="post" id="post-<?php the_ID(); ?>">
<div id="title_container">
<div id="date">
<div class="d"><?php the_time('D') ?></div>
<div class="j"><?php the_time('j') ?></div>
<div class="m"><?php the_time('M') ?></div>
</div>
<div><h2 class="title"><a href="<?php the_permalink() ?>" rel="bookmark" title="Permanent Link to <?php the_title(); ?>"><?php the_title(); ?></a></h2><br />
</div>

</div>

<div class="entrytext">
<?php the_content('<p class="serif">Read the rest of this entry &raquo;</p>'); ?>


<?php link_pages('<p><strong>Pages:</strong> ', '</p>', 'number'); ?>
<br />
<br />
<div id="post_single">
<div id="post_single_title">Author:</div>
<div id="post_single_description"><?php the_author_posts_link() ?></div>
</div>
<div id="post_single">
<div id="post_single_title">Time:</div>
<div id="post_single_description"><?php the_time('l, F jS, Y') ?> at <?php the_time() ?></div>
</div>
<div id="post_single">
<div id="post_single_title">Category:</div>
<div id="post_single_description"><?php the_category(', ') ?></div>
</div>
<div id="post_single">
<div id="post_single_title">Comments:</div>
<div id="post_single_description">You can <a href="#respond">leave a response</a>, or <a href="<?php trackback_url(true); ?>" rel="trackback">trackback</a> from your own site.</div>
</div>
<div id="post_single">
<div id="post_single_title">RSS:</div>
<div id="post_single_description">You can follow any responses to this entry through the <?php comments_rss_link('RSS 2.0'); ?> feed.</div>
</div>
<div id="post_single">
<div id="post_single_title">Navigation:</div>
<div id="post_single_description">
<div class="navigation">
<div class="alignleft"><?php previous_post_link('&laquo; %link') ?></div>
<div class="alignright"><?php next_post_link('%link &raquo;') ?></div>
</div>
</div>
</div>

</div>


</div>

<div id="post_single">
<?php comments_template(); ?>
</div>

<?php endwhile; else: ?>

<p>Sorry, no posts matched your criteria.</p>

<?php endif; ?>

</div>

<?php get_sidebar(); ?>
</div>

<?php get_footer(); ?>