Congratulations on your launch. Not really feedback but I realized when I clicked through that I would have signed up if I could use one of the federated login services (Google most likely, GitHub maybe, Facebook probably wouldn't have helped) and I didn't want to go through the mail, password, confirm cycle so much I actually just hit back.
I think you can still get someone's email for follow up if you use them.
I think you can still get someone's email for follow up if you use them.