I've been told you can simply drop an html element into the landing page and paste the script in, and while that seems to work briefly, the script cannot be seen by google adwords within 24 hours of it being placed. I'm trying to figure out how to access the actual html for a given landing page (not the template, but the page itself), so I can place the script just before the </body> tag, as google recommends. Has anyone done this or had any luck getting a consistent result here?
In this particular case, you have two options:
1. If you plan on using AdWords remarketing on more than a one-off landing page, implement Google Tag Manager—this will allow you to place one snippet of code in your landing page while being able to customize per-page what remarketing scripts are fired. It's free and easy to use. I would highly recommend this solution if you plan on extending out your PPC campaigns.
2. Create a token variable inside the template, which I describe in a little more detail here.
Hey Nick, if you're looking for a quick-and-dirty solution, you should just drag in an HTML element and paste the conversion code in there. It's as close to the end of </body> as reasonable for a one-off fix.
Google says to place the code right before </body> for page loading optimization reasons. It doesn't make an actual impact on whether or not the code will be detected to the remarketing campaigns. If you're making the HTML element last (after you've made the other content elements in the landing page editor), your primary content will load first anyway (with the exception of the footer or code that comes in from the template and not the landing page editor).
As for the code being detected within 24 hours, that's a limitation on the AdWords side, not the Marketo side. You'll have that same limitation whether you manually hard-code the script somewhere versus use Marketo's landing page editor.
As a little alternative to Courtney's approach, I put in backup tokens in the landing page templates for situations like this.
Edward Unthank | Founder, Etumos