In short, we can summarize the reasons why e-mail confirmation is necessary: 1. It's required by law in many places. That's why newsletter/auto-responder servi

In short, we can summarize the reasons why e-mail confirmation is necessary: 1. It's required by law in many places. That's why newsletter/auto-responder services use double opt-in. 2. If someone or something does sign-up on your behalf, why should you have to specifically opt out? So, it's always better to have someone confirm their e-mail, instead of having random users having to "opt out" of services they never signed up for. 3. Many a times, if it's some random site, the activation e-mail can go directly into your SPAM box. If an "opt out" type e-mail ends up in your SPAM box, then you probably won't see it, and it can potentially cause more damage. 4. For features like password reminder, it is always better, security-wise, to send the reset link to an e-mail you know for sure belongs to the account holder. If you mistyped your e-mail, and never received the conformation, you'd try creating an account again. However, if the account was activated by default, and you started using it right away, then you'd have all your e-mails going to someone else. There might be more reasons... I don't see how e-mail confirmation can be counted as "wasted seconds." It is to protect you. It's like taking a backup of your website. Many of them don't do it, because the few minutes it takes doesn't sound worthwhile. However, if the server crashes and your data is lost, only then you realize that those few minutes could have saved months of efforts.