It kind of depends on how you're embedding your signup forms... if you're iFraming a Marketo landing page on each page of your site, and you're using unique landing pages for each page, or if you're just dropping the embed code directly onto the page, or if you're using different forms for different pages, etc.
Without knowing that, it's hard to give you the best direction, but if I go off the assumption you're using one form and embedding it directly onto each page, you could set up a trigger campaign for when that form is completed on specific pages (using the Web Page constraint) and then in the flow steps, place them in the appropriate engagement program.
I agree with Matt, we need more detail on how you are setup now. You could use several options:
- Hidden field for each Form like Lead Source=X but this needs multiple forms
- Hidden field on the Form that pulls in a URL param or other code based on the page they are on.
- Use Fills Out Form on Page Y and Referrer CONTAINS X to ensure correct page (may not really need referrer)
- if these pages are within another Program, like a whitepaper, you could easily use Program Status Changes to capture the leads
- Do you have any unique Product or Solution questions on the Form? That would be the easiest - if Fills OUt Form on Pages XYZ and Solution =X, then Send to Engagement X