<?php
$values = $cfs->get('promoter');
if (!empty($values)) {
    echo $cfs->get_labels('promoter');
    echo implode(', ', array_keys($values));
}
?>
<br />

PromoterPromoter1, Promoter2

Promoter: Promoter1, Promoter2

<?php
$values = $cfs->get('promoter');
if (!empty($values)) {
    echo $cfs->get_labels('promoter').": ";
    echo implode(', ', array_keys($values))."<br />";
}
?>

echo $cfs->get_labels('promoter').": ";

<?php
$values = $cfs->get('promoter');
if (!empty($values)) {
    $word = "";
    $word .= $cfs->get_labels('promoter');
    $word .= ": ";
    $word .= implode(', ', array_keys($values));
    $word .= "<br />";
    echo $word;
}
?>