function post_to_third_party($entry, $form) {

$post_url = 'http://www.autoresponder.com/subscribe';
$body = array(
'email' => $entry['2'],
'Niche' => $entry['5'],
'Date' => $entry['4'],
'IPaddress' => $entry['6'],
'list' => 'autoresponderlistID'
    );

$request = new WP_Http();
$response = $request->post($post_url, array('body' => $body));

function post_to_third_party($entry, $form) {

$post_url = 'http://www.cpvlabs.com/base3.php?id=xxx';
$body = array(
'click' => $click-through,   <---Not sure if this is possible
    );

$request = new WP_Http();
$response = $request->post($post_url, array('body' => $body));