Knowing users hate work, even when necessary, creates a scenario where we must craft processes which encourage success by offering baby steps, validation and reward.
From beginning to end, our relationship with the consumer is about fulfilling their needs and desires. We entice them to arrive at our website through marketing our value proposition and simple directions to our front door - a URL. When they arrive, we instantly confirm that they are in the right place and offer a pleasantly considerate experience.
"Good job, consumer. You found us! Here's our best stuff."
Other users may have clicked an ad unit or an email link. These folks get special treatment. We've learned a bit about them (what brought them to us, what they are specifically interested in) and so, we offer them a special incentive to continue on to the ultimate step in the process - making a purchase. This is where real work comes into play.
As soon as you ask for a user's personal contact information (and especially, their banking information), they all become skeptics. Because we've been working to build value and trust from the beginning, it's fair to expect some users to blindly continue. Just realize plenty will not, no matter what the lead up entails.
"Why do you need all this information? Who are you exactly? Are you trustworthy? How bad do I want this thing? Hmm, I don't know."
Again, remember baby steps, validation and reward. One long form, requesting all the user's personal information, is plainly intimidating - folks will simply bounce. You can (and should) break up the entire process into separate steps with added value, offered along the way.
Offer the user a mailing list sign-up to get their e-mail address. Validate that by sending special offers to their inbox. Encourage them to create a free account (for privileged access) to gather their name, gender and age - perhaps utilize the Facebook login API. Collect their address or ZIP code to reveal localized discounts. Present limited time offers to encourage the purchase and (finally) capture their credit card information. Offer discounted rates for activating automated recurring payments.
In this way you are building unique user profiles. With those, you can more effectively market to and better serve the individual user. As the relationship continues, introduce polls and surveys, log their click paths and interests. Learn, remember and leverage as much as you can about each individual.