Yeah I saw those, but that still restricts a user to a single form for that list. My point is that I'd like to be able to pass those options as hidden input fields in the subscription form itself so that I could use multiple thank you or already subscribed URLs per list, like so:
<form action="
http://mylistsite.com/lists/ha722frmdd713/subscribe" method="post" accept-charset="utf-8">
<input type="hidden" name="SUBSCRIBE_SUCCESS" value="
http://some-other-site.com/thank-you">
<input type="hidden" name="ALREADY_SUBSCRIBED" value="
http://some-other-site.com/sorry-already-subscribed">
<input type="hidden" name="PASS_FIELDS" value="1">
<input type="text" class="form-control" name="EMAIL" placeholder="" value="" required>
<input type="text" class="form-control" name="NAME" placeholder="" value="">
<input type="text" class="form-control" name="FNAME" placeholder="" value="">
<input type="text" class="form-control" name="LNAME" placeholder="" value="">
<button type="submit" class="btn btn-primary btn-submit">Subscribe</button>
</form>
<script>
// basic clientside validation
</script>
This way, I'm not limited to a single URL destination for a form and I - or more importantly, my customers - don't have to learn how to create a URL with query strings since the app could automatically handle appending the query string.
An example is a customer/client that's a real estate agent. They have 0 technical skills, but need to create a lead generation form for multiple properties. They may want to add people to a main buyer list, but based on the property, send them to a different thank you page.
Having even a basic form builder (this would make a great paid extension) that would allow a user to create a form with basic inputs: text, radio, range, selects, check boxes, hidden, text areas, etc and set form handling options would be a huge part of the autoresponder and add some pretty heavy value. I'm more than happy to help develop something like this if anybody's interested.