[Erwin]

Not tested myself, but should work - try this:

In functions.php, find:

PHP Code:

    $post[off]=bbcodeparse($post[off],0,$allowsmilies); 


UNDERNEATH, add:

PHP Code:

  // Get referrals
  if ($usereferrer) {
    $refcount = $DB_site->query_first("SELECT count(*) AS count
                                       FROM user
                                       WHERE referrerid = '$post[userid]'");
    $referrals = $refcount[count];
} 


Then, in your postbit, add this anywhere you like to show the referral count:

Referrals: #$referrals

Should work! However, this will add an extra query per post in a thread to the showthread page. There's no real way around this unfortunately, since the referral count needs a query to COUNT the variable from the database.