What scripts should every LP include?



Geo location. Split-testing script. P202. and pretty much any script to deliver custom info based on the ad.
 
Tracking. Google analytics is free, but some people have beef with using it. Theres another free one out there thats good, but I can't remember the name of it.

I've also heard good things about clickheat, but have yet to try it myself. Allows you to see where people are clicking on your page.
 
use a heatmap like crazyegg. you'll see where people are clicking on your LP and where they're spending time. you can optimized from that.

split testing script would be something to rotate through different landing pages to see which one works best.

you could also use a rotating script to see which offer converts the best or you could also use it to test out the same offer from different networks to see if theres any kind of scrubbing going on.
 
I use this to split test LP's

PHP:
<?php

$link[1] = "http://";
$link[2] = "http://";
$link[3] = "http://";

if (!isset($_COOKIE['link'])){
    $n = count($link);
    $rand = rand(1,$n);
    setcookie("link", $rand, time()+3600);
    header('location:'.$link[$rand]);
}else{
    $go = $link[$_COOKIE['link']];
    header('location:'.$go);
}

?>