Ive updated your code so it includes html code, so people can add to there sites and also updated code so $vboptions[bburl] is in there insted of manual edit of the domain name. Added send to a friend, add a new thread to your forums like a welcome thread to sign up and features of the forums etc and then replace t=2844 to what the thread ID is.
Code:
<!-- ############## START REFERRER BY ADAM GESSEL #################### -->
<table class="tborder" cellpadding="$stylevar[cellpadding]" cellspacing="$stylevar[cellspacing]" border="0" width="100%" align="center">
<thead>
<tr>
<td class="tcat" colspan="7">
<a style="float:$stylevar[right]" href="#top" onclick="return toggle_collapse('usercp_reflink')"><img id="collapseimg_usercp_reflink" src="$stylevar[imgdir_button]/collapse_tcat$vbcollapse[collapseimg_usercp_reflink].gif" alt="" border="0" /></a>
<a href="$vboptions[bburl]/register.php?referrerid=$bbuserinfo[userid]">Refer Friends URL</a><span class="normal"></span>
</td>
</tr>
</thead>
<tbody id="collapseobj_usercp_reflink" style="$vbcollapse[collapseobj_usercp_reflink]">
<tr>
<td class="alt1" align="center" colspan="7">
<b>Invite your friends to join our forum by linking them here via the following link:</b> <br /><a href="register.php?referrerid=$bbuserinfo[userid]">$vboptions[bburl]/register.php?referrerid=$bbuserinfo[userid]</a></p>
<p><b><a href="/sendmessage.php?do=sendtofriend&t=2844">Send To A Frend</a></b></p>
<b>Our add this HTML code to your
site</b></p>
<textarea rows="3" cols="58"><a href="$vboptions[bburl]/register.php?referrerid=$bbuserinfo[userid]">Ive Joined The Forums, Why Don't You?</a></textarea></td>
</tr>
</tbody>
</table>
<br />
<!-- ############## END REFERRER BY ADAM GESSEL #################### -->