I must have looked at the signup.module a half dozen times and thought, why would I want anyone to sign-up for a node when we already have notify.module? Turns out I just wasn’t getting it, and I suspect many others are not as well. The description of the module is very poorly written in terms of communicating its functionality.

The fact is that this little module is a nascent registration system for any number of purposes. It integrates with the events calendar, and you can add a custom registration/sign-up form as an attachment to any event notice or other type of post that encourages sign-up or registration. You do this using the signup.theme file which is at the root of the module directory.

You can alter this user signup form to suit your needs–feel free to alter any elements in this section, remove them, or add any others. In order for the form to be rendered properly, the name of the form element must be in the form of $form['signup_form_data']['NameOfDataField'], where NameOfDataField is replaced with the actual name of the data field. It’s also suggested that the displayed name of the field to the user be the same as the name of the data field, but it’s not required. See below for examples. Note that the example below is meant as a starting template only, and none of these form fields were designed to integrate with existing drupal fields. If that is desired, it will need to be coded.

@return An form array which is the form to be present to the user upon signup to a node

in addition, The 4.6 version appears to integrate with the e-commerce module to allow for payments, though I haven’t tested this yet. The 4.7 version does not do this from what I could see.

Thanks to Amazon (Kieran Lal from CivicSpace Labs) for the tip.