[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?

[JohnFen]

It's no more or less disconnected than any other store purchase. You can assume there are cameras in any store. You can indeed pay cash. The only records generated are the usual sales records, and if you're concerned about minimizing those, then you use the same mitigations that you'd use with any other purchase.

Personally, I'm not concerned with that level of anonymity, though. I just don't want to give my actual phone number to random companies.