[dhx]

Splitting long forms across multiple pages can be detrimental to usability.

As a user, I want to know what information is going to be requested of me prior to commencing completion of the forms. I don't want to reach the payment page after filling in countless other fields to discover that my preferred payment method won't be accepted or the shipping rates are unacceptable. Placing form fields on a single page means that the user doesn't have to hand over information at the risk of not receiving something in return.

Requesting an email address or password multiple times is frustrating too. Hacker News gets this right. To sign up, all a user has to do is type text into two fields, click a button and it's done - ready to use.

[natrius]

"As a user, I want to know what information is going to be requested of me prior to commencing completion of the forms."

What you want doesn't necessarily correlate with what will make a business the most money. I'd bet that significantly more people complete the forms when they're split, and people don't have a significant negative reaction to being "tricked" into a multi-step sign up process.