Hi Peter:
The discussion you're referencing is regarding emails in Marketo, not landing pages. They work a little bit differently--the class="mktEditable" in emails designated blocks that can be edited. In landing pages, this is accomplished through the entire body being "mktEditable" and then dragging in different elements.
For adding any and all elements, you can use the
Double Div method that I wrote about. It does make the WYSIWYG a bit more nuanced to use in achieving this, but it brings in the possibility of using native Marketo dynamic content in the editor. The short version of how to do it is to drag in HTML elements and create your own code structure to wrap those dynamic pieces of content.
When we have complicated landing pages with dynamic content and non-web-developers need ot change/recreate/clone, we can have someone technical put placeholders in the WYSIWYG, then the other Marketo users can clone the landing page and simply replace the elements (such as replacing the picture, editing the rich text content, changing the form, etc.).
Best,
Edward UnthankMarketing Operations Specialist
Yesler