No, I wouldn't call it a demonstration. It's a declaration with no supporting evidence of success. There are many ways to turn this into a meaningful demonstration. For example, you could change the signup page to 2 or 3 linked pages.
Page 1 would be all of the preconsent disclosures and a "continue" button which takes you to page 2.
Page 2 would begin with an explanation and instructions for the "test drive", including:
1. a button to open the test pdf document (a mockup of your deposit statement would appear in a new window),
2. instruction to retrieve a piece of information from the test document ("ending balance" would be nice) and then close the test document,
3. instruction to enter the retrieved information into the single field on this page and then click the "I consent" button ("agree" does not track ESIGN's requirements.)
When the customer clicks the "I consent" button, your server would validate the data submitted. If the data is bad, the server would demand a valid response before completing the opt-in. It might also provide a "help" phone number and anything else necessary to accomplish the opt-in. If correct data was submitted, the server would set this customer's ESIGN flag (only for the account just processed) and capture IP, timestamp, test value the customer entered, and anything else you would like to have in hand if the opt-in is later challenged in court or by an examiner.
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...gone fishing.