[cowsup]

Nope. Almost everybody has more than one device (laptop, phone, and maybe a tablet) with more than one IP (both home wifi and phone data). Everyone has multiple email addresses.

You could get by with requiring a unique phone number, but that still risks excluding users, and can get expensive if you intend on catering to an international audience. Even in that case, some people may have a landline and a cell phone, or they may use a friend/spouse/relative’s phone to circumvent your limits.

[JohnFen]

> You could get by with requiring a unique phone number

In the US, anyway, you can also get burner phones for about $10 at local stores. I do this routinely if someone is requiring a phone number to register for something that I really want to register for.

[bediger4000]

As someone who hasn't been motivated in the past, how disconnected from other means of identification is such a burner phone?

Are the cameras watching the purchase? Can you pay cash? Is any record beyond a sales receipt generated?