Well, then give me self-signup followed by a clearly outlined verification flow that I can follow. If you show me a form where I can upload my passport or enter a random number from a charge on my card, that counts as "instant" enough. If you really need to make me wait a couple of hours while somebody manually reviews my info, fine, just tell me upfront so I can do something else in the meantime. It's all about managing expectations.

Besides, Amazon hands out reasonable quotas to newly created accounts without much hassle, and they seem to be doing okay. It's not about abuse.