Are you a SaaS company using a Marketo form for free trial, freemium or product sign up? I'm looking for insight from someone whose Marketo form connects with a backend database to provision a new user.
What exactly are you looking to do?
In these situations, you don't typically need to provision the user literally from the form, that is, from the browser. Rather, you submit the form and then call a webhook out to your outside service to get a trial key, then send the key via email.
Is the key sent via Marketo email via our system? We're trying to avoid passwords going through Marketo for security reasons.
Well, that's up to you. Either you add the key, perhaps temporarily, to the lead in in Marketo, allowing you to track engagement with that email as you would with others. Or you have the webhook merely request that a key be generated and sent, but the remote system sends the email, which means that outbound email isn't managed by Marketo, though the request itself -- and the rest of their lead data -- is actionable.
If your webhook is running over https:// and you clear the field after sending, then your concern (and I'm not saying it isn't valid) are the few moments when the data is temporarily at rest in Marketo. I certainly don't like storing credentials in Marketo, yet not sure a trial key constitutes a "password." Can the key be used by multiple installations? Does it expire? Does the person still need to create a separate username + password?